The Church of Saint-Louis is located opposite the Castle of Chambord, so don't miss it. It's a small church, with free entry. You can take pictures inside. If you're going to visit the castle it's worth visiting here, too, although the outside does not too special, the interior is very nice. The altars are beautiful despite being tiny, and decorated with fresh flowers. In one window you can see some ceremonial robes. Upon entering you will receive a brochure with information about the church.