Barefoot luxury doesn’t get much more appealing than at Holbox’s chicest hotel, the beachfront CasaSandra. Owner Sandra Perez’s artistic background yielded suites whose white-on-white elegance is punctuated with bright Mexican textiles and colorful hammocks. The restaurant serves blissfully simple seafood dishes like grilled grouper with black sesame and cilantro to a well-heeled international crowd. Daytime, meanwhile, should be reserved for taking advantage of the island’s greatest claim to fame: swimming with whale sharks. These gentle giants congregate in the waters here in great numbers from June to September.