On the Island of Owey there are two lakes, the first is on the clifftops and is easily walked to, the second lake is 50 metres directly below the first lake.
In this short film Iain Miller, descends to the lower lake and paddles to its far end to the Pool of Tranquility. This 8 meter pool lives approx 200m underground at the far end of the lower lake. It sits in silence and in complete darkness with no natural light.
http://www.uniqueascent.ie/the_underg...