I’d highly recommend staying at San Popo. They set up some great tours for us through Belize acaving Expeditions. The ATM Caves and Xunantunich/Cave Tubing were highlights of our trip. The location was a great home base for us. It was a quick 15-20 minute walk into and out of town, with a convenience store right down the road. My husband was nervous about the resident gecko that stayed in the room with us, but he managed :)