On 10 July 2025, the Swiss State Secretariat for International Finance (SIF) recognized the Spanish saltwater lagoon Mar Menor as a legal subject – at least to the extent of granting it access to environmental information. This decision followed a request for information submitted by the lagoon’s legal representative. The case demonstrates that the legal personhood of ecosystems can operate across national borders and opens the door to the enforcement of Rights of Nature even in states that lack statutory recognition of such rights. Could ecosystems like the Mar Menor, in the future, bring damages actions against companies whose activities in another country cause ecological harm?