J.R.R. Tolkien>
The Lord of the Rings /
The Silmarillion
Annúminas was the first capital of the kingdom of Arnor. It was founded on the shores of lake Nenuial by Elendil sometime around the year 3320 of the Second Age. The chief palantír of the North Kingdom was kept there until its downfall.
Annúminas was abandoned sometime in the Third Age (250-850) because of the decline of Arnor and the capital then moved to Fornost. It is hinted that it was refounded and rebuilt in the Fourth Age by King Arathorn II Elessar of the Reunited Kingdom, but there is no direct evidence of this.