WASHINGTON -- With 20 Grand Slam singles titles and two Olympic Gold doubles medals between them, Venus Williams and Serena Williams have already stamped their place in tennis history.

While the 2012 London Olympics tennis rosters are still to be determined, the Williams sisters will be in the nation's capital this summer, taking part in some World TeamTennis.

The Washington Kastles' 2012 season schedule kicks off on July 12, and has some marquee names on the calendar. Here are five reasons to head out to the Southwest Waterfront.

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  • Thursday, July 12: Martina Hingis

    The world's former No. 1 women's singles player leads the visiting <a href="http://www.nysportimes.com/teams/team.aspx" target="_hplink">New York Sportimes</a> in the Kastles' season opener. The 31-year-old is a <a href="http://www.tennis.com/articles/templates/features.aspx?articleid=17082&zoneid=9" target="_hplink">five-time Grand Slam winner</a>, owning <a href="http://www.wtatennis.com/page/Player/Stats/0,,12781~3491,00.html" target="_hplink">43 singles titles</a> and more than $20 million in prize money.

  • Monday, July 16: Venus Williams

    Coming off a disappointing <a href="http://www.huffingtonpost.com/2012/05/30/venus-williams-french-open-agnieszka-radwanska_n_1556525.html" target="_hplink">2012 French Open</a>, Williams will represent the Kastles against the visiting Boston Lobsters. Her original <a href="http://www.washingtonpost.com/sports/othersports/tennis/venus-williamss-kastles-appearance-moved-up-to-avoid-conflict-with-london-olympics/2012/06/04/gJQAL3J4DV_story.html" target="_hplink">July 24 match</a> was moved up to avoid a possible overlap with the <a href="http://www.huffingtonpost.com/news/2012-summer-olympics" target="_hplink">2012 London Olympics</a>.

  • Wednesday, July 18: Sam Querrey

    One of the world's most ferocious serves will be on display when <a href="http://www.atpworldtour.com/Tennis/Players/Top-Players/Sam-Querrey.aspx" target="_hplink">Sam Querrey</a> and the visiting Sacramento Capitals invade Kastles Stadium at The Wharf. At age 19, Querrey turned heads when he reeled off an ATP record <a href="http://espn.go.com/tennis/blog/_/name/tennis/id/2954887/querrey-comes-aces" target="_hplink">10 consecutive aces</a> in a 2007 match against James Blake.

  • Friday, July 20: Chris Evert Fan Reception

    Before the Kastles square off against the Orange County Breakers, <a href="http://www.washingtonkastles.com/teams/article.aspx?article_id=3131" target="_hplink">tennis legend Chris Evert</a> (pictured here at 1978 Wimbledon) will host an event for ticketholders. An <a href="http://espn.go.com/tennis/story/_/id/7626203/chris-evert-signs-four-year-deal-call-tennis-espn" target="_hplink">18-time Grand Slam winner</a>, Evert holds the <a href="http://www.wtatennis.com/player/chris-evert_2257889_2188" target="_hplink">highest winning percentage</a> in pro tennis history (.900).

  • Sunday, July 22: Serena Williams

    Williams returns to D.C. for a <a href="http://www.washingtonkastles.com/teams/article.aspx?article_id=3075" target="_hplink">fifth summer run</a> with the Kastles, and will be the marquee name against the Kansas City Explorers. Like her sister Venus, the 13-time Grand Slam winner was upset in the <a href="http://www.huffingtonpost.com/2012/05/29/serena-williams-french-open-virginie-razzano-upset_n_1554088.html" target="_hplink">2012 French Open</a>, falling in the first round.

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