It contains two stone huts and a possible souterrain. Archaeological digs uncovered an Early Christian souterrain. This is a natural narrow limestone cave with a man-made souterrain at the entrance. The graveyard contains a 9th-century souterrain with several chambers. An example of an excavated souterrain is the site at Rosal, Strathnaver, Sutherland. These invisible people, reside in the souterrain world. Some have suggested a souterrain, a place for storing crops and animals. Within each enclosure was a small stone building and a souterrain. The third entrance visible on the west side of Dowth is an early Christian souterrain. There are a number of souterrain sites within a radius of the centre of Ballymena. In some cases a souterrain (tunnel) forms part of the structure. The term "souterrain" has been used as a distinct term from "fogou" meaning 'cave'. The northern terminal of the souterrain was better preserved, where 3-4 courses of wall survive. Many Souterrain underground passageways were constructed, though their purpose is obscure. These are two passage tombs (known as Dowth North and Dowth South) and a souterrain.