Towering above the streets of the Innere Stadt, this massive cathedral is the true centerpiece of Vienna. St. Stephen's has stood in this very spot since the early 12th century, but little remains of the original aside from the Riesentor (Giant's Gate) and the Heidentuerme (Towers of the Heathens). The Gothic structure standing today was built in the early 1300s and has survived the Turkish siege of 1683.  It was here that mourners came to pay their respects to Amadeus Mozart in 1791. In 1805, Napoleon used St. Stephen's doors to post his farewell edict. And it weathered attacks from both German and Russian armies during World War II. Today, this stunning cathedral remains an active house of worship, a national icon and a top tourist attraction.

After you've toured the main section, head underground to the catacombs where many victims of the Great Plague of Vienna were laid to rest. Move on to the gruft, or vault, where numerous urns contain the remains of members of the Hapsburg royal family. Before you leave, you should climb the 343 steps to the top of the South Tower or use the elevator to reach the lookout terrace at the North Tower – you'll be treated to a spectacular view. Visitors call this one of those "must-visit" attractions in Europe, praising the gorgeous church and its surroundings.