Beneath the pastures and second-growth forest on the border of Greenbrier and Pocahontas counties, there is another country. It has its own rivers, its own weather, its own atmosphere of total darkness and 54 degree air. Friars Hole Cave System runs for roughly 50 miles of mapped passage - the exact number depending on which surveyor you ask, since the cavers who explore it cannot quite agree among themselves. In 2017, the karst geologist William B. White called it the 31st-longest cave in the world. Above ground, the land looks like ordinary West Virginia farm country. Below, a labyrinth older than any human civilization carries on its slow work.
The system has eleven known entrances, scattered across two counties and many farms. Their names read like a folk poem: Friars Hole, Rubber Chicken, Crookshank Pit, Toothpick, Icebox, Snedegars Staircase, Snedegars Saltpeter, Snedegars Stream, Snedegars North, Canadian Hole, Radio Pit. Some are obvious holes in the ground. Others are vertical drops you would walk past without noticing. Five of the eleven are now closed to the public, either for the safety of cavers or for the protection of the cave itself. The Snedegars complex - named for the family on whose land most of those entrances open - alone accounts for four separate ways down.
Friars Hole is dissolved out of the Greenbrier Group, a stack of Mississippian limestone laid down in shallow tropical seas about 340 million years ago when this part of North America was sitting near the equator. The limestone is 300 to 800 feet thick in places. After it was buried and lifted up by the Alleghenian Orogeny - the mountain-building event that crumpled the Appalachians 300 million years ago - the limestone fractured along thrust faults. Acidic groundwater followed those fractures, dissolving the rock millimeter by millimeter, century by century. The oldest passage in Friars Hole is estimated to be 4.1 million years old. The cave is still being made today, every time it rains in the hills above.
What sets Friars Hole apart from many caves is that it is, in part, an active hydrological system. Creeks above ground sink into swallets - the local term for places where surface water disappears - and flow underground through the cave's lower passages before emerging again at springs on the other side of the ridge. Cavers exploring the system sometimes work waist-deep in those streams, in air that is perpetually 54 degrees Fahrenheit and 100 percent humid. Hypothermia is a constant concern even in summer. The cave is mapped in the manner of a 19th-century coastline: in slow incremental expeditions, with hand-drawn surveys, knowing that there is more out there than has been found.
The Greenbrier Valley is one of the great karst landscapes of eastern North America. The countryside above Friars Hole is dotted with sinkholes, blind valleys, and the kind of perfectly round depressions that announce themselves to anyone who has learned to read the ground. Local farmers know which sinkholes will swallow a tractor and which will only swallow a calf. The West Virginia Cave Conservancy and the National Speleological Society work with landowners to maintain access for serious cavers while protecting the cave from vandalism. Friars Hole is not a show cave. There are no lights, no walkways, no gift shop. You bring your own headlamp, your own helmet, your own willingness to crawl through tight passages in cold water in the dark.
Different sources put the total length at 63, 73.4, 77.4, or 82.5 kilometers. The spread is not sloppiness; it reflects the difficulty of measuring a thing that is still being mapped, in passages that branch and rejoin, with surveyors disagreeing about whether certain side leads belong to Friars Hole or to a connected but separate system. The 82.5 kilometer figure - roughly 51 miles - is the most recent and most generous count. In any version, Friars Hole is one of the longest caves in the United States. Mammoth Cave in Kentucky leads the world by a wide margin at more than 700 kilometers. But Friars Hole, in its quiet way, is part of the same family of vast subterranean wildernesses that the limestone of the eastern United States hides beneath its forests.
Located at 38.07 degrees N, 80.33 degrees W on the border of Greenbrier and Pocahontas counties in southeastern West Virginia. The cave system lies beneath rolling karst farmland west of US-219. There is nothing dramatic to see from the air - the entrances are small holes in pastures and woods. The terrain itself, dimpled with sinkholes, is the visible signature. Greenbrier Valley Airport (KLWB) is the nearest tower-controlled field about 15 nm south. Recommended viewing altitude 4,500 to 6,500 feet MSL. Expect ridge-and-valley terrain throughout the area; valley fog common in mornings.