Sian Ka’an is a biosphere reserve. It was established in 1986 and became a UNESCO World Heritage Site in 1987. Part of the reserve is on land and part is in the Caribbean Sea, including a section of coral reef.
Sian Ka’an is located in the municipality of Tulum. You can visit the reserve by booking a tour from Playa del Carmen or directly at Tulum town. Usually you leave Playa or Tulum in the morning, it takes around 2 hours to get there by 4×4, then you eat in a basic restaurant, and get on a boat to visit the reserve. Coming back they stopped at the same town so you can eat or buy typical stones, bracelets or collars.
HOW MUCH ?
The cost is around 120 us$ for the entire day, but there is cheaper offers (like if you go there by yourself, by car or by bike.)