Cavers took a rare opportunity to descend into the gaping mouth of one of Britain's biggest known cave chambers.

Members of the public were winched one by one down the gigantic pothole known as 'Gaping Gill' in what could be described as a journey to the centre of the earth at the weekend.

The complex cave system and spectacular waterfall are situated on the slopes of Ingleborough mountain in the Yorkshire Dales.

It takes one minute to reach the floor of the cave, which is so large the knave of the York Minster could be contained inside it.

Gaping Gill was formed by the Fell Beck stream which flows from the flank of Ingleborough onto limestone rocks and plunges down over an awsome 110 metres drop, forming Britain's highest unbroken waterfall, which is twice the height of Niagra.

The main chamber is 145 metres long, 25 metres wide and 35 metres to the height of the roof.

The cave is only open to the public for a limited time each year, but expeditions organised by Bradford Potholing Club will continue this weekend and all of next week.

Gaping Gill lies on the heart of a natural fault line.