Neuchâtel is a town, a municipality, and the capital of the Swiss canton of Neuchâtel on Lake Neuchâtel. Since the fusion in 2021 of the municipalities of Neuchâtel, Corcelles-Cormondrèche, Peseux, and Valangin, the city has approximately 33,000 inhabitants. The city is sometimes referred to historically by the German name Neuenburg; both the French and German names mean "New Castle". The castle after which the city is named was built by Rudolph III of Burgundy and completed in 1011.