Island of Holbox Mexico Maps & Guide. Going to the Cancun area? Don't forget to visitYum Balam Nature Reserve and separated from the mainland by the Yalahau Lagoon, which is home to flamingos and pelicans. The car free island, situated between the Caribbean Sea and the Gulf of Mexico, is rich in marine life such as sea turtles and whale sharks.This 2 part maps and travel guide of Isla Holbox covers getting to know Holbox, hotels and rental properties; restaurants, bars and beach clubs; tours, attractions and services.