Kinderdijk village is situated in a polder in the Alblasserwaard at the confluence of the Lek and Noord rivers. To drain the polder, a system of 19 windmills was built around 1740. This group of mills is the largest concentration of old windmills in the Netherlands. The windmills of Kinderdijk are one of the best-known Dutch tourist sites. They have been a UNESCO World Heritage Site since 1997.
References:Château de Niort is a medieval castle in the French town of Niort. It consists of two square towers, linked by a 15th-century building and dominates the Sèvre Niortaise valley.
The two donjons are the only remaining part of the castle. The castle was started by Henry II Plantagenet in the 12th century and completed by Richard the Lionheart. It was defended by a rectangular curtain wall and was damaged during the Wars of Religion. In the 18th century, the castle served as a prison.
The present keeps were the central point of a massive fortress. The southern keep is 28m tall, reinforced with turrets. The northern tower is slightly shorter at 23m. Both are flanked with circular turrets at the corners as well as semicircular buttresses. Each of the towers has a spiral staircase serving the upper floors. The Romanesque architecture is of a high quality with the dressed stones closely jointed.