Housed in a beautifully restored Victorian colonial jail on Gabourel Lane, the Museum of Belize covers the country's natural history, archaeology, and colonial past. The building itself — brick and imposing, constructed in the 1850s — is part of the appeal.
Inside, the Maya jade collection is the standout: carved pendants and masks from sites across Belize, including pieces from Caracol and Lamanai. The exhibits on Belize's reef system provide useful context before or after a dive trip. There's also material on the colonial period, the logging economy, and the country's path to independence in 1981.
One of the better small national museums in Central America. Allow an hour.