Okay - so it's not on the beach, and it's not right in the centre of town. But it takes no time to get to the beach - there are always lots of very cheap taxis, get them to take you to 'beach club Paraiso' and rent a lounger near the bar - lovely. Town is only a few minutes walk from the Posada, go via the back streets, it's safer away from the traffic of the main road, is more involving, and you don't see the 'truck stop'. Go diving in a cenote whilst here, hidden worlds are a reliable friendly safety conscious company. Also - top tip - if you intend to travel by coach then take a jumper - they like setting the aircon to super cold!