Kiritimati is the world's largest coral atoll, a remote Pacific outpost of strange history.

Nature · Published 30 September 2026 Swipe more like this →

In short: Spanning 150 square miles, Kiritimati is a massive coral formation in the central Pacific. Once a site for Cold War nuclear testing, this remote island now serves as a wildlife sanctuary, a hub for satellite telemetry, and a unique home to species found nowhere else on Earth.

Kiritimati, also known as Christmas Island, is the largest atoll of purely coral formation globally. Located in the Northern Line Islands of the Republic of Kiribati, it accounts for nearly half of the nation's total land area. While it was sighted by Captain James Cook on Christmas Eve in 1777, archaeological evidence suggests earlier intermittent use by Polynesian people between 1250 and 1450 AD, likely for resource gathering. Permanent settlement proved difficult; a 1902 lease for coconut plantations saw 72,863 palms planted, yet extreme drought eventually killed 75% of them, leading to the island's abandonment from 1905 to 1912.

The island's modern history is marked by strategic and scientific activity. During the 1960s, it hosted nuclear weapons testing by both the United States and the United Kingdom. Today, the landscape is defined by coconut plantations, fish farms, and satellite telemetry stations. Because of its equatorial proximity, the island is a prime location for space-related infrastructure. Despite this, the environment remains sensitive; the entire island is a designated wildlife sanctuary, protecting endemic species like the Kiritimati reed warbler, known locally as the bokikokiko, which has adapted its diet to include introduced weeds.

Life on Kiritimati is shaped by its isolation and the challenges of atoll geography. Most of the land sits no higher than 26 feet above sea level, making it highly vulnerable to rising ocean levels. While the island features a major airport and supports commercial activity, it remains dependent on foreign aid for development. Its unique position in the Pacific—having been shifted west of the International Date Line in 1995—places it in the UTC+14 time zone, making it one of the first inhabited places on the planet to welcome each new year.

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