Almaren was the island home of the Valar in the
time of the Spring of Arda, their first abode in Arda. It was in the
center area of Middle-earth in a great lake, lit by the Lamp of Illuin.
It was there that Tulkas and Nessa were married.
Because of the ruin of Almaren in the second onslaught of Melkor that also destroyed the Lamps, the Valar moved and fortified their new home of Valinor.