Estonia, a European nation of 1.3 million people, has no mountains of its own. In 2012, two U.S. climbers died after falling off a ledge on Palcaraju mountain in the Cordillera Blanca range.

With no mountains—Estonia’s highest point Suur Munamägi rises to 1,043 feet—Pärnu’s windy and flat coastline offers ideal conditions for winter kiteboarding. Lay of the land ...