Fodor's Expert Review Laguna de Bacalar

Some 42 km (26 miles) long but no more than 2 km (1 mile) wide, Laguna de Bacalar is the town’s focal point—renowned for both its vibrant green-and-blue waters and for the age-old limestone formations (stromatolites) that line its shores. Fed by underground cenotes, the mix of fresh water and salt water here creates ideal conditions for a refreshing swim. Most hotels along Laguna de Bacalar rent kayaks and paddleboats; however, there are no beaches or amenities other than those found in rental properties or hotels. English-speaking guide Victor Rosales ( 983/136–2827), who organizes custom excursions throughout the Costa Maya, offers a particularly fascinating tour of the lake's 3.5-billion-year-old stromatolites.