One of the most beautiful Gothic structures in Europe, the cathedral stands 150m (492 ft.) above Lake Geneva. Construction began in 1175; in 1275 the church was consecrated by Pope Gregory X. While in Lausanne, the pope met Rudolph of Habsburg, emperor of Germany and the Holy Roman Empire. The doors and facade of the cathedral are luxuriously ornamented with sculptures and bas-reliefs. The architect Eugène Viollet-le-Duc began a restoration of the cathedral in the 19th century -- and it's still going on! The interior is relatively austere except for some 13th-century choir stalls; the rose window also dates from the 13th century. The cathedral has two towers, with an observation deck 225 steps up one of the towers.