When it comes to travel--especially to ancient sites, which are big business for the tourism industry--very little stays secret.
No list of ancient sites would be complete without The Great Wall of China. Think not much is hidden about it? Think again. Certain parts still remain unknown, such as the stunning Mutianyu, which rests approximately 90 kilometers outside Beijing and can be accessed using public transportation.
Travel to north Ethiopia to visit The Yeha Temple. It's believed to date back to 700 A.D. Later used as a church, this may be the country's oldest surviving building.
And we're just getting started. Check out the full gallery.