Ryedale Windypits
The Ryedale Windypits are archaeologically significant natural underground features within the North York Moors National Park. This series of fissures in the Hambleton Hills, near Helmsley, is located on the Western slope above the River Rye.
Description
Their name is a local one, derived from their tendency to emit gusts of air and steam from their narrow entrances. The phenomenon is caused by warm or cold air rising from the fissures and coming into contact with the air outside the entrance. In winter a steamy vapour rises in puffs or jets from the holes. In warmer months cold air can be felt in the passage entrances, sometimes moving so violently as to vibrate the foliage nearby. There are more than 40 known windypits, but only four windypits have known significant archaeological deposits. These are Antofts, Ashberry, Bucklands and Slip Gill. Due to their geological significance, several of the windypits are designated as SSSIs.The windypits are used as an amenity for cavers and potholers, and are also nationally important swarming and roosting sites for bats. Seven species of bat have been recorded including whiskered Myotis mystacinus, Daubenton's M. daubentoni, Natterer's M. nattereri and brown long-eared Plecotus auritus. All of the Ryedale Windypits are located in or on the edge of woodland or forestry plantation.