Moinhos Velhos

By Ricardo Constantino
Photos: A. Sobreira / SPE 2009

“Old Windmills” is the English translation of Moinhos Velhos, Portugal’s premier cave system. History tells us that Manuel da Troucha, a local sheep herdsman, discovered the cave in 1925, but it was only in 1946 that it was first explored by Francisco Abreu. Francisco Abreu quickly discovered huge rooms, massive tunnels, underground rivers, and many other marvels; the excitement was such that he and friends founded the Portuguese Speleological Society (SPE; in 1948. The histories of SPE and Moinhos Velhos are intrinsically wound, and it remains today one of the Society’s main exploration sites.

"OK, let’s go through the final equipment check: helmet, carabiner, croll..."

The team of GUE cave divers (Delfim Machado, Luis Magro, and Ricardo Constantino) in Moinhos Velhos through the summer of 2009 used these and many other “odd” pieces of equipment to execute a series of exploration dives.

Little did these GUE divers know of what would await them when they first joined SPE, got trained in dry caving techniques, and heard wonderful stories and accounts from the “old timers” about Moinhos Velhos and its Poço Final, the Final Pit—so named because it meant the end of dry exploration in the eastern area of the system.

The adventure started on the weekend of May 31st — by installing water pumps! In the summer, to reach the Poço Final, one needs to pump until dry three (suspended) sumps, which meant installing 200 meters of fire hose, 700 meters of electrical cable, and running the three pumps for over 160 hours to provide a continuous dry access to the dive site, some 1000 meters through dry cave, including three vertical shafts, from the entrance elevator. The last time that SPE had accomplished this feat was back in 1991, and it still impresses the manner in which all this was done.

Finally in the beginning of August, we reached Poço Final; doubles, stages, and dive kits were transported to the site — this by itself took the six-person team on duty that weekend a full two days to accomplish. The weather remained dry and one of the water pumps kept running 24 hours a day to keep the water recharges from refilling the sump. Diving could start!

Between the 2nd and 29th of August, the team did a total of six dives from the Poço Final platform and explored 350 meters of new cave and surveyed a total of 223 meters. Reaching a maximum depth of -47m, the cave heads south…towards a nearby cave system. ;)

Great team work, commitment, and dedication from the almost 30 SPE members involved!

Video & photos:

Parts of Moinhos Velhos are open to the general public and can be visited here:

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