I spent two months in Mexico last year and visited all of the places you mention, bar Cancun, as well as some others in between. Shouldn't have too much problem fitting it all in. The coach services in Mexico are very good.
A day should do for Oaxaca, it's quite pretty, but not all that much to do there. Puerto is a bit of a traveller's mecca and is good fun, we stayed in a really good hostel there, I think it was the Mayflower.
I would recommend Mazunte rather than Zipolite. If you wanted to go to Zipolite as well it is only 10 minutes up the road. Mazunte was really one of the highlights for me, really chilled, lovely beach, and lots of nice little places to eat and drink dotted along the beach. We went to Zipolite for the afternoon, good to watch the surfers and also a bit of a nudist area at one end if you're into that kind of thing! But that aside Mazunte is far better.
San Cristobal and Palenque are also great. When in San Cristobal go for the boat ride through Sumidero Canyon, it's a bit out of town but stunning. Also in Palenque try to get to Agua Azul and the other surrounding waterfalls, drivers will take you around them, well worth it.
Merida is again nice but there is not all that much to do there, although close by are the Cuzama Cenotes which are great. You get a horse drawn cart along the old railway line ride from the nearby village which takes you to each of the cenotes which you can swim in. Merida is also quite close to Chichen Itza so a good place to travel there from if you were planning on going. I would try to get there as early as possible to miss all of the coach trips from Cancun which arrive about 11 as it gets very busy. Although quite impressive I personally preferred the ruins at Palenque though.
I would also add in Tulum, it is just gorgeous and you can stay in little cabanas on the beach.
To be honest I would leave out Playa Del Carmen and Cancun, especially as you have limited time. Playa Del Carmen has been developed a lot in recent years and has become an exepensive tourist resort, mainly just Americans holidaying. Although I've not actually been to Cancun it's worse still from what I've read. Personally I would just spend more time in Puerto, Mazunte and Tulum. Puerto is great to party, Tulum for the gorgeous beach and Mazunte a mixture between the two.
On from Mexico one place I would definately go to would be Tikal in Guatemala. |