I spent three months living deep in the Jungles of the Sian Ka'an Biosphere Reserve; it is an incredible place full of wildlife, birds and varying ecosystems. For the nature lover travelling in Mexico, it is an absolute must.
Sure the road to Punta Allen is a bit less traveled than the Trans-Canada or the I-5, but with a little spirit of adventure, a trusty scooter will take you all the way from Tulum in a gentle three hours. If driving at night, watch out for giant blue crabs on the road - they scream and snatch their claws if you get to close. Keep your balance in check if you are two and getting through the sand bars may require a short walk. Driving a scooter through the biosphere reserve was not only a great way to get intimate with nature, but is ecologically and economically friendly.
There are several companies that offer tours to the Biosphere, Ecocolors is a good choice, Cesiak, Sian Ka'an Tours, Community Tours in Tulum, and others if you look around. Maps are few and far between, but don't worry, the road doesn't branch the whole way from Tulum to Punta Allen, just go south on the coast road and stop along the way as you are surrounded by beauty. Being a small penninsula, you will see beautiful lagoons on one side and the warm Caribbean Sea on the other the entire way. Don't forget to visit the Visitors Center (9Km from the entrance)where you can climb the tower above the jungle and there will soon be a museum to offer more ecological information to visitors.
There are other entrances to the reserve as well, but I only made it to the Tulum entrance. Covering over 1 million hectares , I believe the reserve has something to offer everyone.