Geograph - photograph every grid square

Cavers inside the cavernous main chamber of Gaping Gill during the Bradford Potholing Club annual Gaping Gill winch meet, 2019. Gaping Gill is one of Britain's most extraordinary natural wonders, comprising a vertical shaft entrance which opens out into the roof of a large cavern and extensive cave network.

During the winch meet visitors are, for a small fee, individually lowered 360 ft (110 m) onto the floor of the main chamber via the main shaft. The stream which normally descends the main shaft is temporarily diverted through other potholes nearby and re-emerges in waterfalls pouring through crevices in the roof. Apart from a pale blue shaft of natural daylight, the cave is illuminated with electric lamps.