One of the best ways to explore the mountains surrounding San Agustín is on horseback. There's also decent rafting to be done on the Río Magdalena.

Horseback Riding

Unlike in some parts of the country, the horses available to tourists here are more often than not in fine condition; ask your lodgings to recommend a guide. You can travel by horseback to some of the archaeological sites around town or head out on some epic multiday adventures.