We did the ruins at Tulum a few years back (in February) when we were there on another cruiseline. It was pretty interesting to see, however, we had our 6 month old ds with us and it was EXTREMELY hot (over 105 degrees) and there's NO shade anywhere there. It was miserable for us because we had no water or cool shelter for our ds. I haven't been there since then, but I've heard that it's always very hot there. Had we known that, we wouldn't have gone. If you're interested in that kind of history, it is a good place to see, but make sure you bring plenty of water (from the ship), hats, etc. I would strongly advise not bringing kids there, though.