The best way to explore Aero, Denmark's charming 22-mile island, is by bicycle. Aero's 7,000 residents enjoy local produce sold roadside on the honor system and save on heating costs using one of the world's largest solar power plants. The island also features prehistoric burial sites, one of which holds a full Viking ship. For more information on the Rick Steves' Europe TV series — including episode descriptions, scripts, participating stations, travel information on destinations and more — visit www.ricksteves.com.