The archipelago consists of three islands, the eroded exposed outer rim of a submerged volcano with a caldera with a diameter of approximately 2.2 km (1.4 mi).

The total area of the islands combined is 2.13 square kilometers (0.82 sq mi), and the highest point is 227 m (745 ft) above sea level.

About 10 km (6.2 mi) northwest of the Maug Islands is Supply Reef, a submarine volcano whose summit is 8 m (26 ft) below sea level.

[2] From a European perspective, the Maug Islands were discovered in 1522 by Gonzalo Gómez de Espinosa [es], who named it Las Monjas (The Nuns in Spanish).

[5] During World War I, the Maug Islands came under the control of the Empire of Japan and were subsequently administered as part of the South Seas Mandate.

During World War II, the German auxiliary cruiser Orion rendezvoused with supply ships in January–February 1941 at the caldera of the Maug Islands.