Urkulu (1,419 m) is a mountain in the Basque Country straddling the border between France and Spain. The main feature of the mountain is the remains of a Roman tower topping the summit, erected in the 1st century BC. to commemorate the recent conquest of Aquitaine.
With the summit providing excellent views over the northern and southern slopes alike, it was used as a watchtower in medieval times.
The tower has a truncated-conical shape, measures 19.5 meters in diameter at the base and is 3.6 meters high. Its original height should have been 4.5 meters. The thickness of the walls is 2.6 meters and its interior is filled with the remains of the original stonework.
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.