I'm thinking of going next year with teens. Would probably do Antigua, Lake Atitlan and Peten/Tikal.
Any other recommendations? I'm unsure whether to try and carve out a few days in Belize for beach time. We'd have two weeks. No-one flies direct so you'd need to change in the states so could go into Guatemala City and out of Belmopan.
We like wildlife and culture but also a bit of down time for reading, swimming etc.