Hidden a short distance from the Pequea Creek on a quiet rise of farmland lies one of Lancaster County’s most persistent historical mysteries: a cavern long rumored to shelter a subterranean lake so deep that no rope could reach its bottom. In the spring of 1870, The Daily Evening Express published one of the earliest accounts of this secret place, reporting that the cave—then known as Bosler’s Hole—contained a pool of perfectly clear water embedded in solid rock. Explorers claimed that its surface showed neither inlet nor outlet and that the abyss below harbored strange creatures “devoid of eyes.”
To nineteenth-century readers, the description was intoxicating: an underground lake hidden inside a hilltop, waters of unknown depth, and ghostly fish adapted to eternal darkness. It is easy to understand why the cave quickly entered local lore. Parties armed with ropes, ladders, torches, and tar-poles descended through the funnel-shaped entrance, determined to find the truth. Their reports grew only stranger. From the rim of the sinkhole to the first limestone constriction, they measured thirty vertical feet. Beyond that, the passage narrowed to a two-foot-wide chute plunging another twenty feet into darkness. From this cramped defile, adventurers emerged onto a sloping chamber floor that led to a body of water said to stretch sixty or seventy feet into the gloom.
Using hastily assembled planks, these explorers built a makeshift flatboat and pushed across the still surface. They tried to sound the lake, dropping weighted lines until they finally reached bottom at thirty-five feet. Though not the bottomless chasm of early legend, the pool’s depth remained impressive for a feature entirely encased in bedrock. The water was cold and perfectly clear. Something moved beneath the surface—small, quick, and pale—but no one was prepared to capture the elusive creatures.
For decades, references to Bosler’s Hole appeared sporadically in newspapers and scientific writings. By the time Pennsylvania Caves was published in 1932, the site had acquired a new name: Refton Cave. Its description matched the old accounts in spirit if not in every detail. Later studies would refine the picture even further. When the cave was fully surveyed again in 1974, researchers documented a sinkhole entrance 30 feet across and 20 feet deep, with a gated opening leading to a four-foot-wide shaft dropping 25 feet onto a mound of fallen debris. From there, a large chamber extended 85 feet in length and 40 to 70 feet in width, rising up to 30 feet at its highest point. The northern half of this great room held an underground pond up to 10 feet deep. Shallower than the depths reported in 1870, but still striking for a fully enclosed subterranean basin.
A detailed map drawn in the 1932 edition, still referenced by researchers today, illustrated the configuration of the main chamber and the extent of the pool along the northern wall.
The cave’s geology, once thought to be carved in Ordovician marble, is now understood very differently. The 1974 survey clarified that Refton Cave formed in dolomite of the lower Vintage Formation, which lies conformably atop Antietam schist. The cavern occupies a fault zone running east–west through the entrance area. As groundwater descended along this fault, it dissolved the dolomite where it met the underlying schist, its downward movement blocked by the impermeable rock below. Forced laterally along the contact plane, the water carved the chamber observed today. This process, occurring primarily below the water table, created most of the cave’s form; later vadose action enlarged the entrance shaft and a dome-like chimney to the east.
The subterranean pond, though smaller than the legendary “bottomless lake,” behaves in a way that fascinated early explorers. Tests conducted in the mid-twentieth century showed that its water level rises and falls in close correspondence with the nearby Pequea Creek, lagging by a day or two. No large opening connects the two, meaning water migrates through a network of narrow fissures and pores within the dolomite—an unseen pulse linking the underground world to the surface above.
The “eyeless fish” of nineteenth-century lore has never been verified, but Refton Cave is home to rare and remarkable species that help explain the old stories. In 1936, investigators from Franklin & Marshall College’s North Museum discovered a previously unknown flatworm in the cave’s waters. Described in 1937 by Libbie Hyman, the species was named Sphalloplana pricei, or the Refton Cave Planarian. This small, pale predator survives only in cold subterranean pools and is now considered globally imperiled due to its extremely restricted range.
Further research uncovered a second new species: Caecidotea pricei, an isopod described in 1949 by Herbert Levi. Populations of amphipods also inhabit the pond. These animals spend their entire lives in total darkness, navigating by touch and chemical cues rather than sight. Their ghost-colored bodies would have been startling to early explorers and may well have inspired the tales of “fish without eyes.”
Ecological surveys conducted in the 1960s and 1970s recorded a vibrant invertebrate community throughout the cavern. Hundreds of spiders, microcrustaceans, springtails, and mosquitoes inhabit the air-filled portions. Divers exploring the pond in 1966 found two small underwater pockets on the north wall, confirming that cave development here is still active.
In October 1981, members of the York Grotto conducted a detailed exploration of Refton Cave, documenting its entrance shaft, interior formations, and the condition of the underground pond. Their visit produced the only known photographic record of the cave’s modern appearance, offering a rare glimpse of a site that has remained closed to the public for decades.
A 2008 Natural Heritage Inventory later classified Refton Cave as a site of exceptional conservation value, noting that several of its species are under consideration for federal protection.
Much has been learned, but the mystique endures. Standing at the edge of the gated sinkhole, it is easy to imagine the explorers of 1870 lowering themselves into the earth, lanterns flickering, ropes creaking, and the unknown waiting below. The stories of unfathomed depths, vanishing streams, and pale, sightless creatures capture a rare intersection of folklore and natural history—a place where imagination and geology briefly converge before descending into darkness.
Access Reminder
Refton Cave is located on private property, environmentally protected, and not open to the public. Anyone entering without permission will be subject to prosecution. It is sealed with a steel door and monitored by camera.
Adventure Awaits!
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Resources
- The Daily Evening Express May 17, 1870 – Pequea Township News
- The Mineralogy of Pennsylvania
- Abandoned Rails: The Quarryville Branch
- Refton Cave: York Grotto Image Archive
- Providence Township Comprehensive Plan 2008
- Caves of Southeastern Pennsylvania
- Strasburg Region Comprehensive Plan of 2006
- Natural Heritage Inventory of Lancaster County
- Refton Cave Lancaster County, Pennsylvania
- Caves of southeastern Pennsylvania / compiled by J.R. Reich, Jr. 1974