Yes, most hotel reservations are fully refundable as long as you cancel before the accommodation's cancellation deadline, which is often 24 or 48 hours before your check-in date. If you have a reservation that's non-refundable, you might be able to cancel it and get a refund within a 24-hour period of your booking. Plug in your dates, click on "Search", then you can filter by "fully refundable" to get the best deals available near Office de Tourisme de Saint-Cast-le Guildo.