Shrule Castle, Tower castle in County Mayo, Ireland.

Shrule Castle is a ruined tower house near the village of Shrule in County Mayo, standing by the Black River on the Mayo–Galway border. The de Burgh family built it around 1238; its stone tower and adjacent field are now used to keep sheep.

The de Burgh family built Shrule Castle around 1238 on the Black River at the County Mayo–Galway border; in 1308 John de Burgh received it from his father Richard Óg de Burgh, 2nd Earl of Ulster. In 1570 Sir Edward Fitton took it with a force of McDonnell gallowglass, and a counterattack by Mac William Uachtar, the de Burghs of Mayo and the McDonnells of Mayo failed. William Burke occupied it and passed it to his son John in 1574; in 1610 Richard Burke, 4th Earl of Clanricarde, leased castle and lands to Pierce Lynch of Galway.

The fortress represents a point of conflict between Irish clans and English settlers who fought for control of the region across centuries. These tensions shaped how local communities remember and relate to this place as part of their shared past.

The castle ruins stand on private farmland, so you need to ask the owner for permission before visiting the site. The structures are partially unstable, so exercise caution and avoid areas that appear unsafe or at risk of collapse.

The McDonnell warriors from Knocknacloy attacked the fortress in 1570 in a battle that altered the fate of their leader Calvagh McDonnell. This assault marked a turning point in who held power over the structure and its strategic role in the region.