It is a Site of Special Scientific Interest. The Braid Burn is the principal watercourse, flowing for some through the nature reserve. It is a small river, typically around wide by deep, although subject to significant variation. At this location it is approximately half way along its course from a spring in the Pentland Hills, to its mouth at Portobello. There is a tunnel around long in the vicinity of the House. Blackford Pond lies to the north of the hill, and is popular with families.