Kirimati Island is the largest coral atoll in the world, with more than 100 lakes or ponds dotting the interior that support a huge number of birds. A large bay on the east coast is known as the Bay of Wrecks because so many ships have foundered there. The main settlements are London and Banana.
There are four villages on the atoll: London, Tabwakea, Banana (Banana Wells), and Poland. Extensive coconut plantations support a copra industry, fish farms have been established and a solar desalinisation plant produces fresh water. Kiritimati has half the land mass of Kiribati.
Tarawa is not a single town but a group of islands surrounded by a coral atoll, and apart from the south (linked by causeways), you'll need a boat to get around the main features. The international airport is on Bonriki in the southeastern corner, which also hosts the new hospital and fish ponds.
The central government offices, Parliament building, President's Office and Residence, central post office, bank, library and archives, and various other official buildings (including the Air Kiribati Travel Agency) are all on Bairiki Island.