Vaduz, small capital of Liechtenstein (5,000 inhabitants), has most of Liechtenstein's interesting sites in the heart of the city. The National Art Collection exhibits part of the collection of the princes of Liechtenstein, known worldwide. It also hosts good temporary exhibitions. The Stamp museum, the most renowned in the world, has a great collection of stamps. Over 100 years of European skiing history are exhibited in the Ski museum. If you are interested in the history of Liechtenstein, visit the National Museum. Though the castle, the residence of Prince Hans-Adam II, is not open to the public, visitors can climb to the summit of the hill to enjoy the panoramic view.