Ambergris Caye quickly became the most popular destination in Belize. A community-first feel and an unwavering commitment to its roots have, so far, preserved the island’s notoriously laidback vibe.

Last year, I traveled to Belize for two nights at the all-inclusive Thatch Caye resort. The resort sits on its own private island, and we stayed in a premier overwater bungalow. The stay exceeded ...