One of the charms of Puerto Escondido is that it is still an active fishing town.
They don´t have a real harbour but pull the boats up on the beach, but there are still a fair bunch of guys making a living from the sea and it gives it a bit more of a feeling of being a real town and not just a holiday place.
the first time i saw this, i was VERY VERY concerned for the safety of snorkelers and beach dwellers alike. you will see a boat going about 25 knots, heading straight for the shore. it's not stopping. people begin to notice and start to part on the shore, and they all have scared expressions, and everyone is thinking, "is he going to stop?" then the boat skids onto shore and at the last second, the motor is lifted out of the water, and everyone is shocked and relieved that no one was killed in this maneuver. it's wild. then, the boat is pulled further onto the sand by men who use logs to roll under the boat for movement.
Puerto is all about Surfing, but you can get cultural too, there are some hidden Aztec sites in hills about an hour from puerto, just ask around and try to arange an ride with a cab to get there, I didn't go, but many sources said that is beautifull.