Sanctuary 13 fringes the south-eastern corner of the course to the right of the 13th tee, and consists of a narrow strip of trees with a thick under-storey.

The woodland nature of Valderrama allows arboreal animals to move freely between sanctuaries, and also between the course and properties outside. Such exchanges ensure that excess young can escape from competition with their parents when they mature. Sanctuary 13, on the boundary of the course, performs the important role of staging-post in the local migration of these young animals. Small passages on the boundary fence allow ground animals to quickly find a way through.

Local migration is a little-understood but clearly important phenomenon. It not only reduces competition between members of the same species, but also allows them to take advantage of an ephemeral resource such as a glut of food.

Orchids are spectacular flowering plants. Three species have been found in Sanctuary 13: Broad-leaved Helleborine, Tongue Orchid and the sinister, leafless, parasitic Purple Limodore. Round-headed Knapweed, a spectacular flower usually found on sandy soil, may also be found in this sanctuary.