Umm an Nasan island is the fourth largest island

Island

An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, cays or keys. An island in a river or lake may be called an eyot , or holm...

 in Bahrain

Bahrain

' , officially the Kingdom of Bahrain , is a small island state near the western shores of the Persian Gulf. It is ruled by the Al Khalifa royal family. The population in 2010 stood at 1,214,705, including 235,108 non-nationals. Formerly an emirate, Bahrain was declared a kingdom in 2002.Bahrain is...

, after Bahrain Island

Bahrain Island

Bahrain Island is the largest island within the archipelago of Bahrain, and forms the bulk of the country's land mass while hosting the majority of its population. Around most of the Island of Bahrain is a relatively shallow inlet of the Persian Gulf known as the Gulf of Bahrain...

, Hawar Island and Muharraq Island

Muharraq Island

Muharraq Island is the third largest island in the archipelago of Bahrain after Bahrain Island and Hawar Island. It is named after Muharraq City, the former capital of Bahrain.There are several towns and villages located on the Island, including:...

. It is privately owned by King Hamad bin Isa Al Khalifa, and is off limits to ordinary citizens. It is connected to Bahrain Island

Bahrain Island

Bahrain Island is the largest island within the archipelago of Bahrain, and forms the bulk of the country's land mass while hosting the majority of its population. Around most of the Island of Bahrain is a relatively shallow inlet of the Persian Gulf known as the Gulf of Bahrain...

 through the King Fahd Causeway

King Fahd Causeway

The King Fahd Causeway is a causeway connecting Saudi Arabia and Bahrain. The idea of constructing the causeway was based on improving the links and bonds between Saudi Arabia and Bahrain...

. There is little development on the island other than two palaces for the King and some gardens. There is also a small population of black buck

Black Buck

For the mammal, see Blackbuck. For the RAF operation, see Operation Black Buck.In post-Reconstruction United States, Black Buck was a racial slur used to describe a certain type of African American men...

 introduced to the island.

Umm an Nasan lies in the Gulf of Bahrain

Gulf of Bahrain

The Gulf of Bahrain is an inlet of the Persian Gulf on the east coast of Saudi Arabia, separated from the main body of water by the peninsula of Qatar. It surrounds the islands of Bahrain. The King Fahd Causeway crosses the western section of the Gulf of Bahrain, connection Saudi Arabia to Bahrain....

 in Persian Gulf

Persian Gulf

The Persian Gulf, in Southwest Asia, is an extension of the Indian Ocean located between Iran and the Arabian Peninsula.The Persian Gulf was the focus of the 1980–1988 Iran-Iraq War, in which each side attacked the other's oil tankers...

 to the west of Bahrain Island, and to the east of the Saudi coastal city of Khobar

Khobar

Khobar is a large city located in the Eastern Province of the Kingdom of Saudi Arabia on the Persian Gulf. It has a population of 360,000 and forms part of the greater Dammam metropolitan area along with Dhahran, which together have a combined population of over two million...

.