Thornton Force

• The cliff shows a classic three-layer unconformity: folded basement slates at the bottom, a thin conglomerate boulder bed above them, then Great Scar Limestone. The time gap across that junction is roughly 170 million years.
• The fall exists because of ice-age drainage. At the end of the Devensian glaciation, meltwater ponded behind a moraine barrier at Raven Ray in southern Kingsdale; when the lake overtopped, the new channel cut through the moraine and into the limestone beneath.
• Since that breach the fall has retreated about 60 metres into the hillside. Water also sinks into limestone fissures upstream, with some of it reappearing as Little Thornton Force to the west.

This is not a roadside stop. Thornton Force is reached on foot as part of the ticketed Ingleton Waterfalls Trail, entered at the ticket office at the Broadwood entrance by the viaduct in Ingleton, signposted from the A65. The trail is a 4.5 mile circular route walked clockwise as a one-way footpath, normally taking 2 to 4 hours with an average around two and a half. The path stays close to the two rivers and passes through Thornton and Twisleton Glens, so you get the fall as part of a longer walk rather than a quick detour.

• The operator describes the walk as strenuous, with a large number of steps. Sections are uneven and can be slippery.
• It is unsuitable for wheelchairs and pushchairs.
• Strong footwear with good grip matters more than anything else you bring. Warm waterproof clothing is sensible.
• Stay on the path. Swimming in the river, campfires and barbecues are not allowed. Dogs are welcome on a lead.

The glens are a nature reserve, part of the Thornton and Twisleton Glen SSSI, with sections cared for by the Woodland Trust and areas covered by a Limestone Pavement Order. It is one of the finest places in the national park to see gorge woodland, with ancient semi natural upland ash woodland growing on limestone. Keep an eye on the water: brown trout are commonly seen leaping the falls and dippers are often spotted at water level. Both are possibilities rather than guarantees.

• No formal facilities have been verified at the waterfall itself. Parking, toilets, refreshments, WiFi hotspots, EV charging and picnic areas all belong to the trail infrastructure elsewhere on the route, including the Broadwood car park and the Falls Park area roughly halfway round.
• Mobile data is not available around the trail. Download the operator's self guided geology and ecology guide before you set off if you want the background as you walk.
• Parking at Broadwood is limited and reserved for ticket holders.
• The route is popular and the steps and narrow, uneven sections make it a proper walk rather than a stroll. If steep steps are a problem, this fall will not be an easy target.