Jean-Baptiste-Charles Bouvet de Lozier became the first person to discover Bouvetøya on New Year's Day of 1739. On 10 December 1825, two British sealing ships rediscovered the island, naming it Liverpool Island and taking possession for the British crown. Norway annexed the island in 1928, due to the country's interest in Antarctic whaling, and in 1971 Norway declared Bouvetøya a nature reserve. Bouvetøya is the most isolated island on Earth - the nearest land, the Antarctic Continent, is more than 1600 km away. The island is also the tip of an inactive volcano. Olavtoppen, the island's highest point, is 780 meters tall, and the island is about 49 square kilometres in size. Glaciers, making landings on the island very difficult, cover 93% of Bouvetøya.