Its terrain is a raised coral and limestone plateau, flat to undulating, ringed by vertical white cliffs, approximately nine to fifteen yards high. Navassa's environment is mostly exposed rock. However, it has enough grassland to support goat herds. Dense stands of fig-like trees and scattered cactus also exist. Only one tenth of the island's land is meadows or pastures. Navassa has no ports and only off-shore anchorage.