The complex spreads across roughly ten acres at the foot of Reenconnell hill, overlooking Smerwick Harbour, and what makes it genuinely unusual is not any single monument but the sheer density and variety of what survives from different centuries, all loosely gathered without any visible enclosing boundary. Alongside the roofless Romanesque church, which was probably built in the mid-twelfth century and yet goes entirely unmentioned in the annals, there is an ogham stone, a finely carved sundial, an alphabet stone, a corbelled dry-stone building that may have been a residential cell, two bullaun stones (basin-shaped hollows ground into boulders, associated with Early Christian sites and later folk ritual), two holy wells, traces of a turas or devotional circuit, and a scatter of cross-inscribed grave markers and carved fragments. A cross-slab recorded as recently as 1965 has since disappeared entirely.

The site takes its name from Maolcethair, whose death is recorded in the Martyrology of Donegal under the year 636, described as a son of Ronan, son of the King of Uladh, and as being of the race of Fiatach Finn, monarch of Erin. Though the site is also traditionally associated with St. Brendan, it is Maolcethair who is credited with the foundation. The objects that survive from the Early Christian phase are remarkable in their own right. The ogham stone, an early medieval script incised as notches along a stone's edge, stands 1.83 metres high beside the graveyard path and carries the inscription ANM MAILE INBIR MACI BROCANN, with a second possibly earlier inscription on its reverse. The alphabet stone, now set on a modern base near the chancel arch, bears the Latin alphabet in half-uncial script and an invocation contracted as DNI, short for Domini; the epigraphy has been dated to the second half of the sixth century. The sundial, 1.23 metres tall with elaborately carved geometric and interlaced designs on multiple faces, had at some point been repurposed as a headstone to a modern grave before being moved to its present position at the west edge of the graveyard. By the early fourteenth century the church was listed in the Papal Taxation for the diocese of Ardfert, with a rector named as Philip, chancellor of Ardfert; throughout the medieval period the rectory formed the prebend of that chancellorship, and the chancellor probably occupied the nearby Chancellor's House. As late as 1756, half the tithes of the parish were still attached to the chancellorship, though whether the church was still in use by then is uncertain.

The pilgrim's track to the summit of Brandon Mountain passes through Kilmalkedar, which gives some sense of how the site fitted into a wider landscape of devotion. The altar, a feature at the southern end of a field to the west of the graveyard, and the nearby small cell built into the field wall, are among the quieter details that reward a slow circuit of the site rather than a direct walk to the church door.