That is barely enough room to swing a currach, yet someone, at some point in prehistory, chose this narrow tongue of rock as a place worth defending. The site is known as Doonywealaun, or Dún Uí Mhaoláin in Irish, and it sits just west of Paddock Point, extending roughly 54 metres out to the south-west into the harbour's waters.

A promontory fort is, in essence, a piece of naturally defensive high ground made more so by human effort: where the land narrows before dropping to the sea, a bank and ditch cut off the approach and turn the seaward portion into an enclosure. Here, that earthwork stretches the full 16 metres from cliff edge to cliff edge at the landward end. The outer fosse, a defensive ditch, is nearly a metre deep and around 2.7 metres wide at its base, with the bank behind it rising a further 0.7 metres above the interior. A narrow berm, a flat shelf of ground roughly a metre wide, runs along the outer face of the bank. Whoever built this left a causewayed entrance crossing the defences, a raised pathway through the ditch that would have allowed controlled access to the interior rather than simply breaching the earthwork. The measurements and layout were recorded by J. Cuppage in the 1986 Dingle Peninsula archaeological survey, which remains one of the most detailed inventories of the region's field monuments.

The site rewards careful looking rather than dramatic scenery. The earthworks are modest in scale but legible on the ground, and the proportions of the promontory itself, so narrow that the harbour is visible on both sides almost wherever you stand, give a clear sense of why such a location was chosen. The natural cliffs do most of the defensive work; the bank and ditch handle only the one vulnerable approach.