Forever Young — Mark Dalliston

A young woman decides to spend her gap year in the South of France. She is determined find out whether a town exists where the townsfolk live forever. Even if it turns out to be false, it should make a great article or book. She leaves Australia with two friends. They are going on to work and party in London. She wishes them well but knows her destiny lies elsewhere. Leaving Paris, she bases herself in Lourdes. She finds a town of the same name as the one she read. Is this the same Gaul as described in the book?