Palace of Culture and Science (Polish: Pałac Kultury i Nauki) in Warsaw is just a 30-minute walk from the Royal Castle. The Palace was built in 3 years by 3,500 Russian workers as a gift from Joseph Stalin. Since it was finished in 1955 is has been the tallest building in Poland, its spire reaches 237 metres and the viewing terrace on the 30 floor (114m.) allows you to admire Warsaw from above. The Palace of Culture and Science has 3288 rooms, including Congress Hall which seats 3,000 people, a museum of technology, a museum of evolution and a swimming pool. In year 2000 a second-largest tower clock in Europe was added to the building. Each of its 4 faces has 6 metres in diameter.