The Pangelap group of islands separates Selat Pangelap from Selat Abang.
The Alor Islands, the southernmost of the Pengelap group, consist of some rocky islets lying on a reef; the southernmost islet is 46m high.
Pengelap, the largest of the group, is about 3.3 miles long, N and S, 0.5 mile wide, wooded, and moderately elevated, attaining a height of 80m in the N part; the island is fringed by a reef, which projects in places on the E coast to a distance of 0.25 mile, but on the W coast to a less distance.
Udiep (Oediep), an islet 39m high, thickly wooded, and surrounded by a reef, lies about 1.3 miles E of the N end of Pengelap, and in the channel of Selat Dempo.
Dedap, about 2 miles long, NW and SE, and about 0.3 mile wide, lies about 1 mile W of Pengelap.