Where is the border town of Bitche that has a notable 13th century citadel?

Bitche (German and Lorraine Franconian: Bitsch) is a 'commune' in the Moselle department of the Grand Est administrative region in north-eastern France. It is the Pays de Bitche's capital city and the seat of the canton of Bitche and the 'communauté de communes du Pays de Bitche.'

The town belongs to the Northern Vosges Regional Nature Park and is rated 4-flowers at the towns and villages in bloom competition. The French census in 2013 puts the town's population at 5,225. The inhabitants are known as Bitchois and Bitchoises.

The town is known for its large citadel originating from a castle built at the beginning of the 13th century. The fortress is noted for its resistance during the Franco-Prussian War. Louis-Casimir Teyssier, its commander and chief, held the place for about 8 months with 3,000 men against about 20,000 Prussian and Bavarian soldiers until the French government ordered him to surrender after the ceasefire in 1871.

The town became part of Germany after that date until the end of the First World War when it was given back to France. During the Second World War, it was annexed by the Third German Reich (1940-44).

After 1945, Bitche became one of the busiest military camps where all parts of the French army manoeuvered. Infantry and cavalry also went to Bitche for experimenting with new weapons during the Cold War.

The picture is of Saint Augustin's Chapel.