Cave rescuers have warned people to be careful if they plan to explore an “extremely cold” underground lake. Explorers have been urged to be better equipped to tackle ancient shafts at a famous shale quarry after two people were trapped there.

The Croesor-Rhosydd mines in Eryri have an underground lake. Experienced cavers carry their own ropes and even inflatable boats to cross the 50-meter lake. The boat is left in place to be pulled through the water, but users may experience problems. On a recent visit, a caver had to swim into the deep, icy lake to retrieve the boat. Although the two eventually crossed paths, North Wales Live reports that they were unable to find a way out and had to call for help.

The North Wales Cave Rescue Organization (NWCRO) responded to the call and sent more than 20 teams of volunteers from across the region. It said: “The missing people were located at the base of the first landing… and were assisted. Having trouble with the boat, a man swam across the very deep and extremely cold lake to retrieve it.

“The party continued but were unable to find a way out of Rosydd Quarry at the end of the journey and were forced to retreat to Cresor. This required lifting the ropes into place, something the group was not prepared for. Despite this, they managed to get back to the base of the long first innings, where the NWCRO found them.



In August, NWCRO faced similar circumstances when two cavers attempted to recover a boat from the lake.

For explorers, the quarry offers an “underground adventure” with numerous obstacles. In it, as in the lake, there are ditches and bridges, and cavers have installed ropes. However, all quarries can be dangerous and Lake Crozor Rosydd is particularly difficult without the right equipment – cavers are advised to bring buoyancy. After a series of incidents, there are calls for the mining complex to be closed. In August, NWCRO rescued two other cavers when a boat cable became entangled.

The NWCRO urged people to be very careful. The team said: “NWCRO does not wish to discourage people from attempting the route. However, many groups encountered problems. The boat that is there often gets stuck and it is difficult to cross the lake to get to it. Finding routes in Rhosydd Mine can also be tricky. Anyone planning a trip should think about what to do if things don’t go as planned. “They should at least know the route and use climbing equipment with ropes so they can retreat if necessary.”

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