The fortified citadel at Blaye, standing on the opposite bank of the river Gironde to Fort Médoc, forms, along with Fort Paté, the region's 17th-century defence against river attack.
Built by Vauban, together this group are named the Fortifications of Vauban and are classified as a UNESCO World Heritage Site. The site of the citadel saw its first castle in the 7th century. Vauban's fortress though was built in 1689 and took three years.
The largest of the three fortresses, Blaye has both landward and seaward defences with dry ditches dug out of the rock. He incorporated some of the existing defences into his structure to the benefit of the fort. Some elements are still inhabited today. An impressive spot offering a panoramic view.References:
Kristiansten Fortress was built to protect the city against attack from the east. Construction was finished in 1685. General Johan Caspar von Cicignon, who was chief inspector of kuks fortifications, was responsible for the new town plan of Trondheim after the great fire of 18 April 1681. He also made the plans for the construction of Kristiansten Fortress.
The fortress was built during the period from 1682 to 1684 and strengthened to a complete defence fortification in 1691 by building an advanced post Kristiandsands bastion in the east and in 1695 with the now vanished Møllenberg skanse by the river Nidelven. These fortifications were encircled by a continuous palisade and thereby connected to the fortified city. In 1750 the fortress was modernized with new bastions and casemates to protect against mortar artillery.