While the US and Russia are often seen as worlds apart, they are geographically incredibly close. In the middle of the Bering Strait lie two islands: Big Diomede (Russia) and Little Diomede (USA). The distance between these two islands is only about 2.4 miles (3.8 km). In the winter, an ice bridge sometimes forms between them, technically making it possible to walk from the US to Russia. However, there is a massive time difference: the International Date Line runs between the islands, so Big Diomede is 21 hours ahead of Little Diomede. Because of this, they are often called 'Tomorrow Island' and 'Yesterday Isle.'