Roost Rock

Roost Rock Toothless in the game, Dragons: Rise of Berk.

Official Description
"With a landscape protected by high, nested cliffs, this island is safe from marauding ships. As a result, certain species of Dragons use this location to safely lay their eggs."

- Dragons: Rise of Berk

Geography
According to the Official Description, this island has very high cliffs, that must have many nooks, crannies, ledges, and caves in which dragons can make nests and roost.

Because the Whispering Death, Rushing Death, can be found here, it might be assumed that this island has abundant running water and extensive cave systems.