AAAhh, the ruins are all man-made, what a rip. [actual complaint overheard while reboarding the ship]
Don't have a link for you.
In Progreso, a bus will take you into town. The pier is actually miles out in the sea, you can barely see land from the pier. I've heard the causeway into town is 5 or 7 or 4.5 miles long. Whatever, its a heck of a ways.
Right next to the bus drop off in town you can board a sightseeing ?vehicle? for a tour of the Progreso beach area. Very worthwhile and costs a whole dollar. Plus the vehicles are pickup trucks converted into something like double decker buses, must be seen to be believed. After the tour you might want to just walk back to the beach [3 blocks] and spend time there. Long, nice beach on one side of the street and many bars and restaurants [30 to 50?] on the other side.
Or at the parking lot out on the pier you could catch a taxi for a tour of Mreida [think it was $20 pp]. Merida is a city of over 1 million and its more than 500 years old. Yet ALL the old buildings are so well maintained that you would think they are new. Its loaded with monument circles, beautiful tree lined wide boulevards, and narrow cobblestone streets in Old Town. And it is not a tourist town, its just real.
Or book a ruins tour thru the ship or catch one at the taxi place.
Dan