The Grianan of Aileach is a hillfort atop the 244 metres high Greenan Mountain at Inishowen. The main structure is a stone ringfort, thought to have been built by the Northern Uí Néill, in the sixth or seventh century CE; although there is evidence that the site had been in use before the fort was built. It has been identified as the seat of the Kingdom of Ailech and one of the royal sites of Gaelic Ireland. The wall is about 4.5 metres thick and 5 metres high. Inside it has three terraces, which are linked by steps, and two long passages within it. Originally, there would have been buildings inside the ringfort. Just outside it are the remains of a well and a tumulus.
By the 12th century, the Kingdom of Ailech had become embattled and lost a fair amount of territory to the invading Normans. According to Irish literature, the ringfort was mostly destroyed by Muirchertach Ua Briain, King of Munster, in 1101. Substantial restoration work was carried out in 1870. Today, the site is protected as a national monument and is a tourist attraction.
References:The Château du Lude is one of the many great châteaux of the Loire Valley in France. Le Lude is the most northerly château of the Loire Valley and one of the last important historic castles in France, still inhabited by the same family for the last 260 years. The château is testimony to four centuries of French architecture, as a stronghold transformed into an elegant house during the Renaissance and the 18th century. The monument is located in the valley of Le Loir. Its gardens have evolved throughout the centuries.