Mombasa suburb on the mainland which contains a beach, oil refineries, housing estates etc. Moi International Airport and the Port Reitz District Hospital are in Port Reitz. Mombasa is also a county and divided into six constituencies and thirty wards. Mombasa is a major trade centre and home to Kenya's only large seaport, the Kilindini Harbour. "Kilindini" is an old Swahili term meaning "deep". The port is so-called because the channel is naturally very deep. Kilindini Harbor is an example of a natural geographic phenomenon called a ria, formed at the end of the last glacial period when the sea level
Mombasa and defeated the relief force sent by the Portuguese. In 1632 Dom Jeronimo left Mombasa and became a pirate. That year the Portuguese returned and established direct rule over Mombasa. With the capture of Fort Jesus in 1698, the town came under the influence of the Imamate of Oman, subordinate to the Omani rulers on the island of Unguja, prompting regular local rebellions. Oman appointed three consecutive Governors (Wali in Arabic, Liwali in Swahili): Mombasa briefly returned to Portuguese rule by captain-major Álvaro Caetano de Melo Castro (12 March 1728 – 21 September 1729), then four new Omani Liwali until