That looks cool! Well, maybe not so much in the winter and it makes sense that it would be closed during the pandemic. It sounds like it would be bustling with activity during any other normal, non-plague-ridden summer.
It sort of reminds me of the roman bath in southern Spain. There was a cave with a natural spring inside. A roman arch marks the entrance. I wasn't able to get there with the camera, though.
That would have been cool to see that in Spain! yes like a roman bath, this place is pretty cool. This is just a gentle trickle too, so soothing with the resonance around the cave walls, I could only dream to bathe in a place like this(minus the endangered wildlife). That's too bad you couldn't bring your camera. I can bring mine here but it can get pretty crowded with line-ups to come in and it's hard to take your time for pictures and then get out since everyone trying to come in is blocking the way out...In other words, it's very cozy in there. Obviously same reason it's closed for covid, there is no way to social distance or safe that out either. It will do some good to the eco-system tho, less disturbances to the micro-wildlife.