Akrotiri and Dhekelia, officially the Sovereign Base Areas of Akrotiri and Dhekelia (SBA), is a British Overseas Territory on the island of Cyprus. The areas, which include British military bases and installations that were formerly part of the Crown colony of Cyprus, were retained by the British under the 1960 treaty of independence signed by the United Kingdom, Greece, Turkey and representatives from the Greek and Turkish Cypriot communities. The territory serves as a station for signals intelligence and is thereby part of the United Kingdom's surveillance-gathering work in the Mediterranean and the Middle East.