We went to see the Mayan ruins at Caracol. It's pretty well off the beaten track, and there were only an handful of other people there. It was a 3 hour drive from San Ignacio, time consuming not because of the distance, but the unpaved road. We stopped on the way at the Rio Frio cave which was impressively large. At Caracol, we explored the site with our guide, who explained the various buildings that have been excavated in the last couple of decades. The site was quite large, and surrounded by jungle, and we stopped to watch some howler monkeys for a while. We climbed up the tallest building, thought to have been home to the Mayan nobility in the heat - it felt like a long way up, and there was a good view from the top. On the way back, we stopped at the Rio On pools for a swim, nice and refreshing in the heat.