Petén is Guatemala’s largest state, and a lot of it is in protected national parks to conserve its tropical jungle. The central town, Flores, is a pretty little place on an island in Lake Petén Itza, and from there you can access the most impressive Mayan archaeological sites in Guatemala.
The most well-known is Tikal, but if you feel like playing Indiana Jones you can trek into the jungle to see sites like El Mirador that are still unreconstructed and inaccessible by road. It’s not cheap (you’ll need a guide, mules and food for several days), but to sleep under the stars in the lost capital of the Mayan empire in the depths of virgin jungle isn’t the sort of experience you find often anymore. But you really do need a guide. Unless you have a death wish, or you really are Indiana Jones.
Petén’s high levels of biodiversity attract a lot of ecotourism, and those earnest environmentalist types who spend hours reciting climate change statistics at you, nurse orphaned monkeys back to health, and are so well-meaning they make you ashamed of your selfish ways and resolve to devote the rest of your life to the conservation of the lesser spotted callusticrated tree vole, or some such unlikely-sounding small furry thing. That is, until you realise that it’s swelteringly hot, you can’t move for mosquito bites, and finally convince yourself that you could do more for the callusticrated tree vole by spreading awareness of its plight over a nice cold beer in a pub somewhere.