The entrance is below a small cliff in a shakehole. From the wide overhanging entrance, a short crawl leads onto an dry shaft. At the bottom, an excavated route leads into a narrow stream passage, with a narrow pitch a few metres downstream. Below this, about of narrow passage leads to the top of the third pitch, where the system enlarges dramatically. A pitch passes a ledge, and lands in Fault Chamber, where a vertical geological fault can be seen to have a throw. A further pitch leads to a final chamber and a stream passage. Upstream, the water emerges from an impenetrable fissure, downstream passes through a low crawl before the going eases, passing under some avens. After the passage becomes a waterlogged tube which is normally sumped. This can be baled from the downstream end, to allow a through trip to Dolphin Passage in Death's Head Hole. In Fault Chamber, an easy climb up the eastern rift reaches a small window, that can be forced to an pitch that drops into an independent streamway - High Stream Passage. Upstream leads to an aven with an inlet entering, and a narrow long passage leading to a second aven. Downstream leads into High Stream Chamber where the water sinks in boulders to emerge from the impenetrable fissure mentioned above. A pitch drops into High Stream Chamber from Humble Inlet. Two passages can be reached from the top. Upstream, of decorated passage ends in a mineralised choke on a fault in the area of Humble Pot. The downstream passage is smaller and wetter, and finishes in a blind pit. Short Long Drop is an alternative entrance located from the main entrance. A tight rift leads to the top of an shaft. At the bottom, a tight crawl connects with the bottom of the first pitch in the main cave.
Long Drop Cave was known by the Yorkshire Ramblers' Club by 1922, when S. W. Cutriss described it as: "Long Drop Sink with the cave at the far end, a 10 foot passage leading to Long Drop itself, a perfect round dry shaft, 25 feet deep. There is no exit." The bottom of the shaft was dug by Bob Leakey and Gordon Batty in the 1950s, but without breaking through. The challenge was then picked up by members of the Gritstone Club in 1965, who succeeded in digging down a little further to expose a tight crawl which proved to be the breakthrough point into the main cave. Humble Inlet was discovered by members of the Burnley Caving Club in 1981, when they climbed a high aven in High Stream Chamber. The end of the cave was connected to Death's Head Hole in 1981 by the Gritstone Club. Short Long Drop was dug into and explored by members of the Red Rose Cave & Pothole Club in 2007.
