It all began in 1989, when he swam 200 km in the Ebro River from Logroño to Zaragoza. Since then he crosses lakes, swims in rivers and even straits all over the world. Among those already crossed are Loch Ness, Lake Garda, the Straits of Gibraltar and Magellan as well as numerous Spanish and South American water bodies.
In 2004, the Living Lakes partner organisation "Sociedad Amigos del Lago de Chapala" in Mexico proposed Carlos Peña to swim as a sign of protest against the contamination of Lake Chapala. Thus the contact with the Living Lakes network had been established and other Living Lakes followed.
Following, all lakes of the netowrk Living Lakes are listened, through which Carlos Peña swam.