Built by the MacNamara family, the castle features distinctive wicker-centred vaults and an original cross-wall that sets it apart from earlier structures in the region. A piece of hazel from the vault centering has been radiocarbon dated to 1299-1395, confirming its medieval origins. The building later passed to Pierce Creagh in the 17th century when Charles II granted him the property. It’s sometimes called Dangan Uí Bhigín, later anglicised to Dangan Iviggin, possibly to distinguish it from nearby Danganbrack tower house and another County Clare castle also called Dangan.

Originally a rectangular three-storey structure measuring 16.9 metres north to south and 11.9 metres east to west, the building has since been reduced to an L-shaped plan following the collapse of its southeast corner sometime between the mid and late 19th century. The roughly hewn limestone walls, reaching up to 2.6 metres thick, rest on a pronounced base-batter and display numerous put-log holes where the original scaffolding beams were inserted during construction. The interior reveals two long, narrow double-height rooms with wicker-vaulted ceilings; the northern half of the eastern room still survives, showing opposing joist hangers at different heights that indicate multiple floor levels existed beneath the vault. Various architectural features remain visible throughout, including ogee-headed windows, defensive loops, and garderobe chambers with corbelled roofs in the southwest corner.

The building’s defensive and domestic elements are accessed via two separate staircases: a narrow mural passage within the south wall connects the lower chambers to the upper floors through a series of tight winders, whilst a main mural staircase runs along the inside of the east wall. Despite heavy ivy growth and partial collapse, the surviving architecture displays sophisticated medieval construction techniques, from the carefully positioned window embrasures with wicker-centred soffits to the complex internal arrangement of living spaces. The mixture of defensive features like yett-holes and fortified openings alongside more refined elements such as the twin ogee-headed lights demonstrates how these hall-houses served both as fortified residences and comfortable homes for the Gaelic nobility of medieval Ireland.