what are some amazing things to do in tulum?
State: Quintana Roo
I would not miss Muyil/Sian Ka'an, and any of the nearby cenotes (Cristal, Talaveras, Gran, Cristal, and Zacil Ha). For more info see this page:
website. Two other amazing sites are the Tulum and Coba Ruins.
I second lena's message: at the Chunyaxche Archeological Zone in Muyil walk down the nature path to the lagoon...there you will find boats for tours of the mangrove channels. Available also through Centro Ecologico Sian Ka'an (CESiaK) in the reserve itself. Arrive in Tulum as early as you can because the tour buses from Cancun start showing up at 10am. In Coba you can still climb the pyramid, which you can't do at Tulum or Chichen Itza anymore.