The on-site museum at the entrance to the archaeological zone, providing context for the ruins with original sculptures, ceramics, and jade artefacts recovered from Uxmal and surrounding sites. Scale models of the principal buildings are useful for understanding the site's layout before or after exploring the ruins.
The museum is air-conditioned — a genuine consideration in the Yucatan heat — and takes about 30 minutes to walk through. Visiting before entering the ruins gives you a framework for what you'll see; visiting after allows you to match objects to their architectural contexts.