Aktau (Kazakh: Ақтау - Aqtau; Russian: Актау - Aktau) is a city in Kazakhstan's Mangyshlak Peninsula and country's only seaport on the Caspian Sea. It is the capital of Mangystau Province in the western Kazakhstan. Aktau literally means "white mountain" in Kazakh, so named after the cliffs overlooking the sea. Aktau has a block system - that's why streets of the city have no names and all addresses in Aktau consist of three numbers: the block number, the building number and the apartment number.