Pantano de los Suspiros (English: Swamp of Sighs) is a fan-made introductory adventure for the Spanish roleplaying game Aventuras en La Marca del Este. Since Adventuras is based on retro versions of Dungeons & Dragons, the stats are largely compatible with any old school D&D derivatives.

The hunt for a missing innkeeper's daughter leads to a haunted temple in the swamp. Intended for four 3rd level PCs, at least one of whom should be a cleric.

Written by El Dado Inquieto, but David Macauley helped with the English translation.