The distance across is about 20 miles (30 km) from Ras Menheli in Yemen to Ras Siyan in Djibouti. The island of Perim divides the strait into two channels. The eastern channel, known as the Bab Iskender (Alexander's Strait), is 2 miles (3 km) wide and 16 fathoms (30 m) deep. The western channel, or Dact-el-Mayun, has a width of about 16 miles (25 km) and a depth of 170 fathoms (310 m). Near the coast of Djibouti is a group of smaller islands known as the "Seven Brothers". 