The Gulf of Aden is a gulf located in the Arabian Sea between Yemen, on the south coast of the Arabian Peninsula, and Somalia in the Horn of Africa. In the northwest, it connects with the Red Sea through the Bab-el-Mandeb strait, which is about 20 miles wide. It shares its name with the port city of Aden in Yemen, which forms the northern shore of the gulf. Historically the Gulf of Aden was known as "The Gulf of Berbera", named after the ancient Somali port city of Berbera on the south side of the gulf. However as the city of Aden grew during the colonial era, the name of "Gulf of Aden" was popularised.