In Costa Rica, the area where the sea meets the land is known as the maritime land zone, ZMT, and it’s controlled by laws that define this boundary calculated inland from the average high tide. The maritime land zone is considered national territory owned by the State of Costa Rica, meaning it can’t be sold or owned privately over time.
However, it is possible to lease some of this land under a Costa Rica concession agreement, and in very rare cases there are private titled beachfront properties that do not fall under the maritime land zone law. The main law that governs this maritime zone is called “Ley de la Zona Marítima Terrestre” or Law 6043.