"It took 424 years to build this Gothic showpiece, but considering the hundreds of sculptures jutting out from the facade, the timing is almost understandable. At 466 feet tall, the Strasbourg Cathedral was, from its completion in 1439 until the mid-19th century, the highest Christian structure in the world. Today, it’s fallen to sixth place, but its frontispiece is still considered one of the greatest medieval picture books of all time. Inside, a gander at the 12th- to 14th-century stained glass and organ (with parts dating back to 1385) is optional, but climbing the spire’s 322 steps to enjoy panoramic views over the city as far as Vosges and the Black Forest is pretty much obligatory. Make sure your visit coincides with the 12:30 p.m. hour, when the cathedral’s astronomical clock comes alive with apostles parading before Christ."