The town of Castlegard, France, plays a key role in the 2003 film called "Timeline," but it is a fictional location and does not exist in real life. The pivotal battle described in the film as taking place in April 1357 during the Hundred Years' War is also a fictional detail.
In the film, the town of Castlegard is near the La Roque Castle. In reality, there is a small castle in Normandy called Chateau de la Roque, which was not built until the 17th century. The film is based on the novel by Michael Crichton of the same name.