The structure, which measured over 14 metres long and nearly 8 metres wide, featured thick stone walls built from roughly hewn migmatite boulders and red sandstone, sitting on projecting plinths. The building had opposing doorways with chamfered limestone jambs, and its roof was supported by a central row of octagonal stone columns; three of these were found during the dig, with punch-dressing that suggests they were added in the 14th or 15th century, likely replacing earlier wooden supports. Buttresses had been added to the exterior walls in a second phase of construction, and crude stone flooring survived in places inside.

This hall may well be the stone house mentioned in a 1333 inquisition, later recorded in 1556 as ‘the ruined house called Erles stone’ and in 1636 as ‘Clogh-In-Early’. A mid-17th century pictorial map shows it as a church-like structure with round-headed windows and labels it ‘The old buildings of the illustrious Lord, Richard de Burgo, the Red Earl’. After the medieval hall fell into disuse, its interior was repurposed as a smelting works in the 16th century, and in 1686 a county courthouse was built directly on its foundations, which in turn gave way to the Custom House that stands there today.

The excavations also revealed other significant medieval features on the site, including the eastern corner of a 13th-century castle, a limekiln, and the aforementioned smelting works. Along with these structures, archaeologists recovered an impressive 11,553 artefacts and environmental samples. What makes this site particularly special is its unique continuity of public ownership; from medieval hall to county courthouse to custom house, this patch of Galway has remained in public hands from the 13th century to the present day, a rare example of civic continuity spanning more than seven centuries.