Playa Pescadores sits just south of the Tulum ruins, close enough that boat trips can look back toward El Castillo from the water. It is one of the classic beach stops on this stretch: pale sand, turquoise water, fishing boats, and a steady trade in short snorkelling excursions.
It is busier and more commercial than a lonely beach fantasy, so come with realistic expectations. The advantage is convenience and setting: you can pair it with the archaeological zone, swim afterward, and still feel how the coast and the ruins belong to the same landscape.