Royal Coster Diamonds is a famous diamond-cutting factory in the heart of Amsterdam, next to the Rijksmuseum and the Van Gogh Museum. It is a popular tourist attraction with 340,000 visitors annually from all over the world. It offers tours in more than 15 languages and has an impressive collection of loose and set diamonds, including some of the world's most famous diamonds, such as the Koh-i-Noor.