Built in the late 1230s or early 1240s by Jordan de Exeter, one of the Norman lords who carved up western Ireland amongst themselves, this fortress was strategically positioned to control both the river crossing and the surrounding lowlands. The castle’s name derives from ‘Baile-Atha-lethain’, meaning ‘Town of the Broad Ford’, and in its heyday it anchored a now vanished settlement and served as the stronghold from which de Exeter, as Sheriff of Connacht, launched campaigns against the Gaelic clans until his death in battle in 1258.

The castle’s most dramatic moment came in 1316 when Fedhlim O’Conchobhair, King of Connacht, stormed the fortress in a bloody assault. According to the Annals of Loch Cé, O’Conchobhair burned the town and slaughtered the garrison, killing Stephen de Exeter, Miles Cogan, William Prendergast, John Staunton and “a countless multitude” of defenders. Despite such violence, the de Exeter family gradually assimilated into Gaelic culture over the following centuries, eventually adopting the name Mac Síurtáin, or Mac Jordan, as Anglo-Norman control over the region waned.

Today, the castle ruins reveal centuries of modification and rebuilding. The polygonal curtain wall, which follows the natural contours of the rock, encloses an area roughly 45 metres north to south and 40 metres east to west. The impressive twin-towered gatehouse at the eastern entrance, likely added around 1260, features elongated D-shaped towers that once rose three storeys high, complete with portcullis and drawbridge over a defensive ditch. While much of the structure has collapsed, visitors can still spot fascinating details: 13th-century wall sections supported by tall arched buttresses, 16th-century gun loops added during later modifications, a garderobe chute, and even a late fireplace built into the northern curtain wall. The northern gatehouse tower preserves its barrel-vaulted ground floor chamber with defensive arrow loops, whilst grass-covered foundations within the courtyard mark where timber and stone buildings once housed the lord’s family, servants and garrison.