Even if you're not the kind of traveler who wants to check off as many destinations as possible in a week-long vacation, you might get restless staying in one place for that long. With some cities, you not only have the option of visiting another region, you can also stamp your passport by going to a whole different country for a few days.
The proximity of many European countries makes including multiple countries in one trip easy, even if it's a relatively short holiday. With 7-10 days, you can have a leisurely visit in two countries with any of the "two countries in one trip" combinations featured here.
Going to Germany? Why not include a visit to..
Poland?
Germany's capital city of Berlin offers a fascinating peek at some of the 20th century's most important historic moments. This city, formerly split in two, retains two (some might say more) identities. It's an art and culture lover's nirvana, always changing while still honoring its past.
After spending a few days in Berlin, seeing the Brandenberg Gate, the famous Ku'damm, the palaces and parks and museums, you can hop on a train bound for Poland's capital city of Warsaw.
The Polish capital was heavily bombed during World War II, but - unlike Berlin - has been carefully reconstructed in many places to how it looked before the war. Underneath the historic surface, however, Warsaw is another city that's embracing modernity.
The train from Berlin to Warsaw is about six hours one-way, so you'll probably want to see if you can get an open-jaw ticket (fly into one city and out of the other) rather than having to back-track on the train.
Czech Republic
The city of Dresden in the eastern part of Germany is known to many (especially history buffs) as having been nearly destroyed by Allied bombs during World War II. There are still visible scars in the historic center, but Dresden has been rebuilt to such an extent that you may not even notice the remnants of war.
When you've seen the Dresden sights - including the former palaces of the Kings of Saxony, the rebuilt Frauenkirche, and the bustling Neumarkt - cross the border to the Czech Republic for a few days in Prague.
In under three hours you go from a city almost completely leveled during the war to one that was mostly untouched. Prague's historic center is long on charm and scenery, with expansive squares, ornate churches and cobblestone streets. There's a hilltop castle, a moving collection of sights in the former Jewish Ghetto, and plenty of great beer to be sampled.
If you've got the itch to explore even further, consider a day trip from Prague to the Czech village of Cesky Krumlov - it's a medieval town that routinely takes visitors' breath away.
Going to Spain? Why not include a visit to...
Morocco?
Visitors to the sparkling Costa del Sol can spend their days alternating between Malaga's beautiful beaches and the historic center. This is one of the world's oldest cities, dating back to the eighth century B.C. In addition to the historic sights, Malaga also retains indications of the various cultures that have ruled this region over time, giving the city a fascinating architectural vibe.
A quick glance at a map will show you that it's but a hop, skip and a short ferry ride from the southern tip of Spain to the northern tip of Morocco. So when you've soaked in Malaga's African influences and you're ready for more, head south for the Spanish port city of Tarifa and take a ferry across the Strait of Gibraltar to Tangier.
The Moroccan city of Tangier has long been an important port; the city dates from the fifth century B.C. Like the southern part of Spain, this area of Morocco has also been ruled by many different cultures over the centuries, giving this North African city a distinctly international feel. Walk through the old medina, pick up souvenirs in the bazaar, and visit the historic kasbah. Enjoy some traditional Moroccan fare before heading back toward Spain - or, if you can't squeeze it all into one day, you can spend a night or two in Tangier.
Tarifa is roughly 100 miles from Malaga, and you can take a bus from one to the other if you don't have a rental car. The ferry from Tarifa to Tangier takes only an hour or less.
Portugal
Andalusia's capital city of Seville charms and inspires from the outset. It may be a large city, but the historic center can make you feel like you're wandering the streets of a tiny Spanish village. The ornate buildings blend architectural influences the way Seville has blended its cultural influences - a former minaret is now the bell tower on the cathedral, for instance.
Visit the stunning Alcazar palace, bask in the glow of perfect public squares like the Plaza de Espana, take in exciting flamenco performances, and be sure to get a midday nap to enjoy Seville's nightlife. Then head for the nearly-forgotten other inhabitant of the Iberian Peninsula - Portugal.
You can either hop on a short flight or rent a car to take in the gorgeous scenery on a trip from Seville to Lisbon, the Portuguese capital city.
Lisbon is a city built on seven hills, which means you're never short on great views - or the kind of workout that erases any guilt for indulging in the city's excellent food. Like Seville, Lisbon also boasts a fascinating assortment of architectural styles, including the iconic 16th-century Belem Tower near the Tagus River. Red roofs seem to cascade down the hills into the river, and each of Lisbon's hills has a unique neighborhood identity.
If you're short on time, a flight from Seville to Lisbon is definitely the way to go - it takes less than an hour to connect the two cities. The drive is a little more than 285 miles (4.5 hours by car or 6.5 hours by bus), so it's a good idea to look into an open-jaw ticket to avoid back-tracking.
Going to France? Why not include a visit to...
England
The magic of Paris is impossible to deny. This city boasts so many "must-see" attractions it's tempting to think you'll have your bucket list nearly complete with just a few days in the French capital. There's the famous Eiffel Tower, the art history master class of the Louvre, the beautiful Notre-Dame Cathedral, and so much more. Paris won't give up all her secrets in one visit, but she makes it delightful - not to mention delicious - to discover them slowly over many return trips.
Although there's no such thing as "enough time in Paris," it's hard to ignore the allure of a side trip to another of the world's greatest cities, London - especially when it involves a train ride underwater.
London is both perfectly English and utterly international, modern and steeped in history. You can see Westminster Abbey and Buckingham Palace, the enormous art collections of the museums around Trafalgar Square, and set your watch by Big Ben. Then step into today with a trip around the London Eye for some of the best city views you'll get anywhere.
In less than 2.5 hours, you can get from Paris to London by train, which means croissants for breakfast in a Parisian cafe followed by fish from a London chip shop for lunch. The Eurostar train zips you underneath the English Channel, all the way from Paris Nord to London St. Pancras. If you prefer an above-ground route, you can also take a bus to Calais, a ferry to Dover, and then a bus to London - but that's at least an eight-hour trip.
Germany
It can be easy to mistake the tiny Alsace region in the easternmost part of France for being more German than French. The region changed has hands several times, giving it its own unique flavor that is both French and German and yet neither one completely. The Alsatian capital of Strasbourg is a perfect place from which to explore the region. The historic center is laced with canals and cobblestone streets, many of the buildings look distinctly Alpine, and typical wines are mostly white and Germanic.
With all that German influence - and after indulging in so much French-German food and wine - you might as well pack up for the short train ride to the span town of Baden-Baden in Germany's Black Forest.
The famed Black Forest region in Germany is known not only for its natural beauty but also its thermal spas - Baden-Baden was even a spa resort for the ancient Romans. The city has long been a popular vacation destination, for health and relaxation purposes, visited by Queen Victoria and Dostoevsky, among others. There are still thermal baths in Baden-Baden today, and you can visit the excavated Roman baths, too. It's also ideal for visiting the sights of the Black Forest in between spa treatments.
The train from Strasbourg to Baden-Baden takes less than a half-hour, so you could absolutely visit a German spa on a day trip from Strasbourg. If you want a more leisurely trip, however, stay a night or two in the Black Forest.
Going to the Netherlands? Why not include a visit to...
Belgium
The Netherlands may not occupy much space on a European map, but the port in Rotterdam is the largest on the continent. The port's importance aside, however, Rotterdam is one of the many overlooked Dutch cities -- most visitors just don't look beyond Amsterdam. There's a major university in Rotterdam, giving the city a youthful and international atmosphere, and although much of the historic city center was bombed by the Germans during World War II, the city skyline has developed to be architecturally varied and bold.
After a few days in Rotterdam -- shopping, museum-hopping, concert-going -- you can hop on a train to curl south and then west, ending up in the quaint Belgian city of Bruges.
Bruges is one of the largest cities in Belgium, but that's all relative - the city remains small enough to feel like a village, particularly in the historic center. The whole of the historic center is a UNESCO World Heritage Site, with a network of picturesque canals lined with medieval buildings, ideal for a few days of leisurely strolling, shopping, sightseeing and eating. Don't miss a chance to hear the gorgeous cacophony of bells that comes from the city's 13th-century bell tower.
The train from Rotterdam to Bruges takes less than 2.5 hours total, with a train change in Antwerp. This is actually a great start to a trip that continues moving south into Paris or elsewhere in northern France, if you want to include three countries in one trip.
Luxembourg
For as historically important and aesthetically beautiful as Amsterdam is, it's best known by many tourists as European party central -- and with good reason. The Dutch do everything with focus, from being exceptionally hard workers to celebrating with a gusto you'll be hard-pressed to find elsewhere. You might go to Amsterdam for the festivities, but don't miss the incredible collection of masters at the Rijksmuseum, the 14th-century Oude Kerk, or the moving Anne Frank House.
After a few days of excess in Amsterdam, perhaps you'll be ready for a visit to the capital of one of Europe's smallest countries -- Luxembourg.
The capital city shares its name with the country, and roughly a fifth of the population lives in the capital. Luxembourg's central position in Europe has given it significance over the centuries that belies its small size -- even today, Luxembourg City is home to several European Union bodies. The entire city is a UNESCO World Heritage Site, thanks in part to its historic fortifications, which were completely reconstructed in the 1990s. Visitors enjoy its well-preserved historic buildings, its manicured parks, and its many exceptional restaurants. World War II buffs shouldn't miss the Luxembourg American Cemetery and Memorial in nearby Hamm, where General George S. Patton is buried.
A flight from Amsterdam to Luxembourg City takes less than three hours, but if you have a little more time you can take a train in just over five hours. Because there's a train change in Brussels on the way, you could also make this a three-country trip by stopping in Belgium first before heading on to Luxembourg.
Going to Austria? Why not include a visit to...
Hungary
Austria's capital city of Vienna has a musical and artistic history that carries right through the present. This is the city of Schubert, Strauss, Mozart, Beethoven, Liszt, Brahms and Haydn, and there are many performance halls in Vienna. Once the center of the Hapsburg Dynasty, this city is also home to several former Royal Palaces - the Hofburg and the Schonbrunn being two of the most notable examples - as well as more than 100 art museums. This highly cultured city brings its refinement right into the dining room, too - you'll marvel at the perfect pastries adorning Viennese shop windows.
With a few days (and many cakes) under your belt in Vienna, you can take a train to another cultural capital in nearby Hungary.
Budapest is Hungary's capital, and one of Europe's largest cities, though it was historically two cities - Buda and Pest - that were combined into one. The two cities occupied different banks of the Danube River, and each maintains its identity despite becoming one unified city in 1873. The list of UNESCO sites in the city is long, and with good reason. Everywhere you look, there are spectacularly beautiful structures - including Buda Castle, Matthias Church, Fisherman's Bastion and the Chain Bridge. Budapest is like a gift that keeps on giving, and it feels like a European bargain besides.
Trains from Vienna to Budapest take less than three hours, and leave regularly throughout the day.
Slovakia
It can be hard, walking through the historic center of Salzburg, to get "The Sound of Music" out of your head - placards advertising guided tours are there to remind you at every turn - but this city is about much more than that musical. Salzburg is an internationally appealing university city with a well-preserved historic center (it's on UNESCO'S list of World Heritage Sites). This is the birthplace of Mozart, whose childhood home you can visit. Salzburg is also home to the beautiful Mirabell Palace and its colorful gardens and an enormous 11th-century fortified castle on a hill.
Just when you start to feel you're about to go spinning through the hills like Maria, you can high-tail it out of Salzburg for the Slovakian capital of Bratislava.
Like the Hungarian capital city, Bratislava also sits on both sides of the Danube River. Part of the former Czechoslovakia, it became capital of the newly-formed country of Slovakia in 1993. Bratislava's old town is the center of touristic activity, with a medieval fortification that is the city's oldest structure and a complex of medieval buildings that used to be the Town Hall. On a hill overlooking the city is Bratislava Castle, dating from the 10th century and rebuilt in the 1950s after a fire in the early 1800s. The city also sits within the foothills of the Carpathian Mountains, which gives visitors plenty of beautiful natural scenery and outdoor recreational opportunities.
A four-hour train ride (with a train change in Vienna) takes you from Salzburg to Bratislava, or you can maximize your daylight sightseeing time with an overnight train between the cities. The overnight trains take just under six hours.
From Vienna, a jaunt to Bratislava is even easier - the train takes just 30 minutes, making it easy to visit a second country on a quick day trip.
-- Contributed by Jessica Spiegel for Viator
All photos courtesy of Viator