Kiritimati—also officially called Christmas Island and not to be confused with Christmas Island in the Indian Ocean—is a Pacific Ocean atoll in the northern Line Islands and part of the Republic of Kiribati. The island has the greatest land area of any coral atoll in the world: 642 km2 (248 square miles). Indeed, it comprises over 70% of the total land area of Kiribati, a nation encompassing 33 Pacific atolls. Kiritimati was discovered by Europeans on December 24, 1777 by Captain James Cook. Kiritimati is the Gilbertese spelling of «Christmas» (in Gilbertese, the «ti» combination is pronounced «s«; thus «kee-rees-mass»). Presently, there are four villages on the island: London (the main village and port facility), Tabwakea, Banana (Banana Wells), and Poland. Banana is near the airport (Cassidy Airport) but may be relocated closer to London to prevent contamination of the groundwater. Many of the place names in the island date from Father Emmanuel Rougier, a French priest who leased the island from 1917 to 1939 and planted some 800,000 coconut trees there. He lived in his Paris house (now, only small ruins) located across the Channel (main entrance to the lagoon) from Londres (or London, which he established as a port). La colline de Joe (Joe's Hill) is the highest point on the atoll (less than 12 m above sea level) near Artemia Corners.