You’ll want to find a comfortable seat in the lounge or on the Sun Deck today as your ship cruises through the Wachau Valley. Over the eons, the Danube cut a gorge through the foothills of the Bohemian Mountains, resulting in a 19-mile (30-kilometer) stretch of riverine scenery so beautiful; UNESCO declared it a World Heritage Landscape. Castle ruins dominate hilltops; baroque church towers appear on the riverbanks, marking historic villages and splendid abbeys; and vineyards and apricot orchards cling to the rocky slopes. Some of Austria’s finest white wines are produced from grapes grown on the dry-stone terraces above the river, where grapes were first planted 2,000 years ago.