The small, compact Portal Tomb of Annaghmore is located within a small enclosure next to the road in the townland of Annaghmore (in Irish, Eanach Mór), southeast of Mohill in the southernmost part of County Leitrim, Ireland. Portal Tombs, found in Ireland and Britain, refer to megalithic structures where two equally tall, upright stones with a doorstone in between form the front of a chamber, covered by a partially massive capstone.

This well-preserved and picturesque Portal Tomb has two portal stones, measuring 1.6 meters and 1.3 meters in height, two side stones, a slanted and broken endstone, and a weathered capstone measuring 2.2 meters by 2.1 meters, and 0.5 meters thick. The rectangular chamber measures 2.5 meters by 1.2 meters and stands at 1.55 meters in height.

To the west of Mohill lies the Portal Tomb of Cloonfinnan.