22 Photos of the world's most popular tourist attractions

Koblenz is an ancient city in central Germany, and a gateway to the terraced vineyards and ruined castles of the Rhine Gorge. In the center, a monumental statue of William the Great marks the confluence of the Rhine and Moselle rivers. A cable car connects to the hilltop Ehrenbreitstein Fortress, which hosts museums and cultural events. South along the river is the neo-Gothic Stolzenfels Castle with its gardens.