British Speleological Expedition to the Cantabrian Mountains of Northern Spain, 1965
in conjunction with the "Espeleologos de Penalba", Leon
|British Speleological Expedition 1965 Report|
At Fries on the N634, about 5 miles from Arriondas going towards Ribadesella, there is a very large resurgence cave at the foot of a cliff, from which water is used to power a grain mill.
A 10' high passage goes back for about 50' ending in a deep pool from which the water runs. The passage appeared to continue below the water, but two attempts to free dive into it failed due to the cold water and strong current. Just inside the entrance in the roof, a 2' high passage leads off to the south. At one place there is a pool in the floor and shortly after it becomes muddy and rather narrow. The length explored was about 50 feet and it appeared to be heading back towards the cliff face.
From Fries a dry valley goes up high into the hills to the South East. About 1½ miles along this, high up the South-west side;, below a small cliff, and near a large chestnut tree, is a cave. Prow the 7' high entrance you descend at about 10° for 30' until you reach a chamber 30' high and partly filled with flowstone and stalagmite bosses. A hole at the side leads to a crystal chamber below the floor which proves to be false. No way on can be seen and the system appears to be very old with no sign of recent activity.