The Diomede Islands are a pair of rocky islands located in the middle of the Bering Strait between mainland Alaska and Siberia. Though the two islands are only 3.8 km apart and clearly in a single group, they are separated by the International Date line which also marks the international border between Russia and the United States. Big Diomede is owned by Russia and Little Diomede is owned by the USA. Additionally, Big Diomede is 23 hours ahead of Little Diomede owing to the International Date Line that passes between them, because of this they are sometimes called Tomorrow Island and Yesterday Isle, respectively.