I push through the heavy wooden door and gasp as I look up. This is not what I expected. As the door closes behind me, the gushing sound of the adjacent waterfall cuts out and is replaced by the quiet echo of a hypnotic drip, drip, drip, while gentle plumes of warm steam swirl around my body.
Low-set yellow lights gently flicker against rough limestone walls, subtly illuminating a dark but lofty cave, where narrow walkways weave among ancient stalagmites and discreet wooden benches sit…

