It is situated at the entrance to the Bab-el-Mandeb Strait, which links the Red Sea to the Indian Ocean (via the Gulf of Aden) and is one of the most active and strategic shipping lanes in the world. Yemen has an area of 527,970 square kilometres (203,850 sq mi), including the islands of Perim at the southern end of the Red Sea and Socotra at the entrance to the Gulf of Aden. Yemen’s land boundaries total 1,746 kilometres (1,085 mi). Yemen borders Saudi Arabia to the north (1,458 km/906 mi) and Oman to the northeast (288 km/179 mi).