Built around 1625, it was never a parish church or a place of communal worship. It was a mortuary chapel, a private structure raised by a single family to house their dead and mark their standing among the living.

The chapel belonged to the Magan family of Umma House, also recorded as Umma More, landowners with connections to both Umma and Togherstown in Westmeath. By 1826, a contemporary account described it as a decayed chapel and the ancient place of sepulture of the Magan family, a phrase that captures both its purpose and its condition even then. The building is small, roughly seven metres by four and a half metres internally, with limestone rubble walls about seventy centimetres thick. What makes it architecturally interesting is the quality of detail that survives. The entrance in the south-west gable is a pointed rebated doorway, its jambs cut from punch-dressed limestone, with traces of external render still visible on the stonework. Above the door sits a niche, now empty, which almost certainly once held the armorial plaque of the Magan family, a carved display of heraldry that would have announced whose chapel this was to anyone entering. Beside the doorway, a yett hole remains visible on the north side; a yett was an iron gate or grille fitted to a doorway, common in buildings where security or formality mattered. The north-east gable holds a triple-light flat-headed window with cut stone mullions, a hood moulding above it on the exterior face, and the bar holes of an iron grille set into the stone. The window even retained, at some point, a twin-leaf wooden shutter secured by a draw bar that passed through a purpose-built slot in the mullion itself. A small niche in the north wall may once have held a memorial tablet. The ivy covering the north-east end of the chapel makes that section harder to read, but the south-west end remains relatively clear and the architectural logic of the whole is legible enough.