Definition: An elongate hill, streamlined in the direction of ice flow and composed largely of glacial deposits.

Drumlins occur widely on Orkney – George Mackay Brown likened the drumlins of Harray to sleeping whales.  Each drumlin is a small hill, tending towards an egg shape, with its steepest slopes and summit at the up-ice end. Drumlins rarely occur singly, however, and are found in groups or swarms, with the tapered end of each hill pointing in the direction of glacier flow. Together the drumlins give a streamlined, undulating terrain, with intervening boggy depressions which has been termed basket of eggs topography.

This hill is made of boulder clay resting on rock. The rock surface is rough and may represent an old shore platform that predates the last ice sheet. The lower part of the boulder clay is grey and contains many stones derived from erosion of the underlying grey sandstone. Underlying striations indicate that this old ice flow was from ENE to WNW. The upper red boulder clay is  derived from erosion of the red to yellow sandstones of the Eday Beds in SE Shapinsay. This sandstone is the same type of rock used to build St Magnus Cathedral. Ice flow was from SE to NW. Overall, the cliff exposure reveals a long sequence – marine erosion, two phases of ice flow, and deposition of the thick red till and its shaping into a drumlin form. Today, we have marine erosion again and the hill is destined to be destroyed.