We have allocated 2 full days to go on tours, which would you recommend? We would like to go to Chichen-Itza, would you recommend also Coba (for zip-lining), x-caret park or xel-ha?
Thanks.

They do not have ziplining at Coba; it is an archeological site between Tulum and Chichen Itza.

Chichen Itza is a very long day - but can be done. Coba is another ruin which still allows you to climb the pyramid.

Xcaret and Xel-ha are similar in that both have snorkeling and other things to see - there are differences - a good website to see the similarities and differences spelled out is http://www.locogringo.com/research/eco-parks.html Find out when the cruise ships are in the area and avoid either of these parks on those days.

It sounds like you are not renting a car, but this is something that I would encourage you to think about. Chichen is a very easy drive and you want to get there as earlier as possible - like leave the coast around 5:30am or 6am (sunrise) if you are trying to do this as a day trip. It becomes very crowded by late morning and it does get hot!

If you have a car then you can explore the more isolated beaches and go snorkeling in Akumal's Half Moon Bay.

Depends what you like to do.
Good Luck!

I second the renting a car to get around just be sure you understand the driving rules of the road in MX if you do. The road to Coba and further on to Chichen Itza has been widened from Tulum to about 3/4 of the way to Coba and medians have been installed. After that it's still an ok road to drive on just without the shoulder or medians. The new topes have been clearly marked in that area. Getting to Chichen Itza early is important if you want to avoid the crowds and heat -it opens at 8 a.m. We usually bring a cooler in the car to stock with water and soft drinks for ourselves or to hand out at the military checkpoints if the guys want one. There was a checkpoint on the way to Coba last week but was not a problem.

I wonder if Where To is thinking about doing a tour (and not do-it-yourself) - Alltournative does a tour to Coba that includes a zipline, but it doesn't take place at the ruins.

But...I agree...much easier to DIY, rent a car and it's much, much cheaper!!

Playa.info does a tour there too. I just went with them to Ek Balam last week and, although I'm not a tour person, there were only 10 people in the van and it was an excellent time. Visited the site, went to swim in a cenote and ate a late lunch in Valladolid. My first time down years ago I took one of those big tour buses to Tulum and Xel Ha which I've never done again. I was by myself last week so I didn't feel like driving all that way alone.