On one rainy afternoon in San Ignacio the owner of the hostel I was staying at recommended I pick up a chicken bus and head to Xunantunich. (It took me many times seeing/hearing the name to not mess it up, which seemed to be the case with others I met.) I hadn't been adventurous enough to try the chicken buses in Guatemala, but she insisted it was easy so I took her advice.
It was good advice, and the bus system was so easy to use. Xunantunich was across a river, which was bridged by a cable-cranked ferry that cars and pedestrians share. After a long uphill walk and a super cheap admission, there were a bunch of ruins that definitely beat Guatemala's Tikal.
There was something about it. It was more open and you could see further. There were fewer people there, and most everything was climbable, so it felt like having the place to myself.
In San Pedro, on the opposite side of the country, I managed to snorkel for the first time. The last time I'd tried was when I was 14 or so, in frigid North Carolina Autumn weather, and that went... poorly. This time I was able to at least look underwater. But spending so much time with my back to the extreme sun, well, my skin had better days.
There's a zoo in Belize that's 30 minutes or so outside Belize city, so you can take a chicken bus to it. It's a really nice zoo with a lot of room for the animals. Although it's along a highway, it's really in the middle of nowhere, so waiting for a chicken bus afterward is a rather placid experience.