The church at St. Johnstown was meant to replace the decaying parish church of Taughboyne in 1622, when Sir John Stewart Kent secured permission from the Council Table to build a new place of worship. Despite his £100 contribution towards construction, the project stalled after only the side walls were erected. By midsummer of that year, when the church should have been completed, it remained unfinished; and whilst the original Taughboyne parish church was repaired in 1627 by rector Thomas Bruce, the St. Johnstown church was left to the elements. Local tradition, recorded by Fagan in 1846, confirms that the building never received its roof.

Today, the ivy-covered ruins form an equal-armed cruciform structure measuring 18.9 metres by 6.4 metres internally, with rubble walls approximately 77 centimetres thick that survive to heights of one to two metres. The church’s architectural details remain visible despite centuries of neglect: gaps in the north and south walls of the transepts mark where windows once stood, whilst a splayed window opening survives in the east wall of the south transept, now home to an ash tree growing from its sill. Only a small section of the south wall of the eastern arm remains exposed through the vegetation.

The interior has become thoroughly overgrown over the centuries, with ground levels varying considerably due to successive burials both within the church walls and in the surrounding graveyard. These ruins serve as a peculiar monument to 17th-century ecclesiastical ambitions that fell short, leaving behind a skeletal structure that has stood roofless for four hundred years, slowly being reclaimed by nature whilst still maintaining its distinctive cruciform footprint in the Donegal landscape.