- Beachside Bliss on Ambergris Caye Adults-only resort and spa near the Mexico Rocks Marine Reserve Revel in an idyllic island getaway at Costa Blu Beach Resort part of Trademark Collection by Wyndham. Just seven miles north of San Pedro Town the adults-only retreat is surrounded by Belizes natural beauty and spectacular Caribbean views. Go snorkeling and diving at the nearby Mexico Rocks Marine Reserve take advantage of free kayaks and paddleboards or simply enjoy the serenity of the non-. - 22 ROOMS - 2 LEVELS .