First of all, I want to say that this is the best website... I am a new cruiser in my mid-20s and will be traveling with my mother (55 and also new to cruising). We both want to see as many Mayan ruins as possible (without flying). However, although mom is young at heart, she tires easily, particularly when walking or hiking. She would prefer to look at the ruins from a strategic mid-point, while I'd like to walk all over the place (and climb them, if possible).
Carnival offers a Western Car. cruise w/ stops at Key West, Belize, Cozumel, and Progreso/Merida. RCCI offers Belize, Costa Maya, Cozumel, and Grand Cayman. The main reason I prefer Carnival is because we'd be able to go to Uxmal or Chitchen Itza easily from Progreso, but RCCI offers a longer amount of time in port stops (kind of strange, but anyways). So, ultimately, do you think that Uxmal and/or Chitchen Itza would be too physically demanding for Mom?
Chicen Itza is a very loooooong drive to get to from the coast. its also a lot of walking. its pretty big and spread out if i remember. i dont no anything about Uxmal unfortunatly. If you have a stop in Cozumel your better bet would be Tulum. its a lot closer and its more centrally together than Chichen Itza. there is like a truck type thingy that drives you up to the ruins and then most of the stuff is in one area. also its in a beautiful location. right on the water. its not as big as Chicen Itza though. the Tulum tour is often packaged with a stop at a water park called Xel-Ha which i thought was fun. there is snorkeling or just relaxing there.
We went with my parents in their early 70's to Tulum this fall. The ruins are much more compact than Chichen Itza, but they were not able to climb up to the top for the best views. They did enjoy it though. We tried to go to Xel-Ha afterwards, but it was just too much for one day for them and for my husband too! I would just do Tulum and then do some shopping in Cozumel afterwards.
I have been to Tulum, Chichen Itza, Uxmal and Dzbilchaltun. Personally if your mother does only one Mayan ruin I would recommend Uxmal - beautiful, extensive but more compact than Chichen Itza. When I did the Uxmal tour there was an 85 year old woman who did everything except climb the main pyramid. She just moved slowly and rested frequently. There are some small climbs (up steps) and at one we gave her a little assistance where the steps were uneven.
Chichen Itza is impressive and except for the main pyramid there are no steps to speak of BUT there is more walking and fewer places to sit than at Uxmal.
If Uxmal and Chichen Itza sound too challenging Tulum is very pretty and small - so only very physically challenged people would have difficulties there.
Dzbilchaltun is interesting and has a great little museum and a cenote BUT the ruins are not as impressive and there is a lot of walking.
We went to Dzbilchaltun while in Progreso. It is very nice. We had great guides who gave a lot of Mayan history. There is a nice cenote there for cooling off. I am in my 53 and tire easiky also. This was just right.
We did Chichen Itza from Progresso last January and even though the excursion ran about 7 hours, the ruins were spectacular and were the highlight of our cruise. Having a guide take you through the ruins is a must do.
The bus trip in is long, but the guide's explanation of the history of the Maya made the trip interesting.
However, Chichen Itza is a workout - it is extremely hot and spread out so there is a fair amount of walking, the only stairs are up the pyramid - a must do if you are physically able to do it. I am in my mid 50's and quite fit and it stretched me to the limit so this trip might not be for your mother.