Along the road to Tikal [1] leading to the village of San Miguel is Petencito Zoo (8 a.m.–5 p.m., $3), housing a collection of local wildlife, including jaguars, monkeys, and macaws. The intrepid can ride the concrete water slides here, though their safety is questionable and at least one death has been reported.
Links:
[1] http://www.moon.com/destinations/guatemala/peten/tikal-national-park/tikal