Tulum is really three places — the ruins on the cliff, the 10 km beach road, and the inland town — plus the cenotes and the Sian Ka'an reserve on the way in and out.
Zona Arqueológica de Tulum
The walled Maya port on the cliff, open 8:00–17:00 with last entry at 15:30; 265 pesos for foreign visitors and 80 for Mexicans. Go at opening — there is no shade and the coach groups land mid-morning.
Cenotes on the Cobá road
Gran Cenote, Cenote Calavera and the Dos Ojos system all sit along the Cobá road within about 10 km of town, each with its own gate and its own fee. Most require you to shower and skip sunscreen first, and most take cash only.
Sian Ka'an via Muyil
The easiest way into the biosphere reserve is through the Muyil archaeological zone, 25 km south-west on Highway 307, open daily 8:00–17:00 at 145 pesos for foreigners and 80 for residents. A boardwalk from the ruins leads to the lagoon boats and the float down the old Maya canal.
Cobá
Inland Maya city 47 km north-west of Tulum, with a lake, long raised causeways and a mostly unrestored core; bicycles and pedicabs cover the distances between groups. Climbing the Nohoch Mul pyramid is no longer allowed.
Playa Paraíso and the beach road
Public beach access sits at the north end near the ruins; most of the rest of the beach road is beach clubs charging a minimum spend for a lounger. Cycling out from town is the cheapest way to see it, and the bike lane runs most of the way.