Four days suits Tulum well, balancing the ruins, beach time, and cenote diving that together make up the destination's core appeal. Day 1 starts with the Tulum Ruins, and the timing matters more here than almost any other stop on this itinerary — arrive as close to opening as possible, both for softer light on the clifftop Mayan structures and to beat both the heat and the crowds that build steadily through the morning. The site itself sits directly above turquoise Caribbean water, making it one of the most photogenic ancient sites in Mexico. Spend the rest of the day at the beach, choosing a beach club with a day pass for loungers and food rather than relying on limited public access alone. Day 2 is for cenotes, the freshwater sinkholes that riddle the jungle around Tulum. Gran Cenote and Dos Ojos are both accessible and beautiful, suitable for snorkelling without diving certification, while Dos Ojos in particular connects to a vast underground cave system that certified cave divers can explore further. Bring or rent snorkel gear, and go relatively early, since popular cenotes do get busy by midday. Day 3 reaches further afield to the Sian Ka'an Biosphere Reserve, a UNESCO-listed wetland south of town. A boat or kayak tour through the reserve reveals mangroves, lagoons, and wildlife in a genuinely different landscape from the beach and jungle you've seen so far. Day 4, if you have it, offers a choice between a slower beach day and a day trip to the Coba ruins, a less-crowded alternative to the more famous Chichen Itza, where you can still climb one of the pyramids — a rapidly disappearing experience at Mexico's most famous archaeological sites. A few practical notes: rent a bicycle for getting around, since it's the most practical way to move between the inland town (Tulum Pueblo), the ruins, and the beach road without taxi costs piling up. Tulum Pueblo is considerably cheaper than the beach road for both accommodation and food, so basing yourself there and cycling to the beach saves real money. And check current sargassum (seaweed) conditions if pristine beaches are a priority, since levels vary seasonally and can affect the beach experience.