Marakei is a small atoll in the North Gilbert Islands. The central lagoon consists of numerous deep basins and surrounded by two large islands which are separated by two narrow channels. The atoll covers an area of 13.5 km². The total land area of Marakei is 14.13 square kilometers. A road circles the island and is 26 kilometers long while the length of the island from the airport and running through the lagoon to Teraereke at southern portion of the island is 9.93 kilometers.
It widest width can be found in the village of Rawannawi and narrowest width at Temotu at the western side of the island. Marakei is one of only two islands in Kiribati that encircles its lagoon. The Marakei lagoon is saltwater and deep in some areas, but not tidal. Two narrow channels, which are not navigable at low tide, link the lagoon with the sea; these are called Baretoa Pass and Raweta Pass. Rawata Pass was the location of an obstruction in 1912 after inter-village conflict.