The period from 1600 to 1800 sees the continuing Spanish colonization of Guam and the Mariana Islands as well as sporadic contact between explorers and islanders in the other Micronesian archipelagos. In 1783, the English explorer Henry Wilson is shipwrecked in Belau in the Caroline Islands. Objects collected on the voyage show that the classical traditions of Belauan art are already flourishing during this period. Elsewhere in the Caroline Islands, the ruling chiefs of the Saudeleur dynasty on Pohnpei continue to build onto the megalithic city of Nan Madol. In the years leading up to 1800, however, the city begins to decline and is eventually abandoned around 1820.