The first people of the Northern Mariana Islands navigated to the islands and discovered it at some period between 4000 BC to 2000 BC from South-East Asia. They became known as the Chamorros. Their language was named after them. The ancient Chamorro left a number of megalithic ruins, including Latte stone. The Refaluwasch, or Carolinian, people came to the Marianas in the 1800s from the Caroline Islands. Micronesian colonists gradually settled the Marshall Islands during the 2nd millennium BC, with inter-island navigation made possible using traditional stick charts.