Sumeru is the polar center of a mandala-like complex of seas and mountains. The square base of Sumeru is surrounded by a square moat-like ocean, which is in turn surrounded by a ring (or rather square) wall of mountains, which is in turn surrounded by a sea, each diminishing in width and height from the one closer to Sumeru. There are seven seas and seven surrounding mountain-walls, until one comes to the vast outer sea which forms most of the surface of the world, in which the known continents are merely small islands. The known world, which is on the continent of Jambudvipa, is directly south of Sumeru.