Elizabeth Reef

Elizabeth Reef, located at 29°57′25″S 159°4′32″E, is a coral reef in the Coral Sea. The reef is separated by a deep oceanic pass, some 47 km wide, from nearby Middleton Reef, both of which are part of the underwater plateau known as the Lord Howe Rise. It is around 150 km from Lord Howe Island and 600 km from the New South Wales coast of Australia. The Environment, Sport and Territories Legislation Amendment Act 1997 included Elizabeth Reef in Australia's Coral Sea Islands Territory.

It is the southernmost coral atoll in the world and one of the southernmost platform reefs in the world. It measures 10.5 km by 6.1 km. Despite the relatively high latitude, a wide variety of flora and fauna exists on the reef and in the surrounding waters due to their location where tropical and temperate ocean currents converge.

At low tide most of the reef flat is exposed; at high tide, both a cay and a sand spit are visible. Elizabeth Island, with a diameter of about 50 m, is one metre above sea level. Elizabeth and Middleton Reefs form the Elizabeth and Middleton Reefs Marine National Park Reserve managed by the Government of Australia under the Natural Heritage Trust.