Just within the last few years, indigenous ruins were found in a small town near Penjamo. It is worth visiting if you can get there. It is in a quaint little town, where the local people know that any outsider has come to see the "pyramids". Follow the main, rock road all the way up to the top of the town (it is the only road in town that is not dirt). Parking is up the steep, rock hillside next to the museum. You enter the museum at the bottom of the hill. There was an entrance fee, but it wasn't much (less than $5USD, but they would only let me pay with pesos, no dollars or cards). A guide will bring you through the museum, explaining the artefacts found in the ruins that are on display, then you are free to make the trek even further up the hill to see the pyramids themselves. Some local children will probable offer to accompany you and tell you about the ruins. The hike is short, but very steep. Once you get there, don't miss the entrance to the left, where you can actually go up into the ruins and see the ancient building up close. There is also a great view of the valley from up there. There was an area to buy food or crafts as you come back down, but everything was closed when we went (later in the afternoon on a Friday).