Maynooth Castle, stronghold of the Earls of Kildare, de facto rulers of Ireland in the late Fifteenth century. The family fell spectacularly from power, rebelling against the king in 1535, causing their castle to be largely destroyed and their garrison all killed. Restored between 1630 and 1635, it was destroyed again in the wars of the 1640's. Today only the ruins of the keep - once the largest in Ireland, and of the main entrance gateway survive. It is a sorry remnant of what was once one of the most impressive castles on the island. A castle was built here shortly after the Norman invasion in 1179. This was rebuilt and significantly enlarged in 1426. The ruins that are left betray this history of building and rebuilding.