Photo by Sonia Tenbarge ’28 for The Lafayette

A spelunker’s perspective of Lost River Caverns.

The obligatory geology lab many students take to fulfill their natural science requirement may come in handy for this local “underground” weekend activity: caving. Yes, there are caves in the Lehigh Valley.

“Since we have a temperate climate, the size at which caves form tends to be smaller,” cave specialist and geology professor Elizabeth Patterson said. “We get the really fun caves where you have long passageways.”

At the deepest point of Lost River Caverns in Hellertown lies its namesake, a river located nearly 116 feet below the ground. Tourgoers can even hear the running water below them as they explore the cave.

“The cave started forming over 250,000 years ago,” said tour guide Maddy Garcia at Lost River Caverns. “It’s a baby cave.”

No one knows where the river leads, Garcia explained. The Gilman family, who have owned these caverns since 1930, have tried everything: ping pong balls with contact info, biodegradable red dye accompanied by a newspaper announcement and also a person (who is alive) — to no avail.

Another mysterious aspect of the cave is an illustrated white star on an overhanging rock featured on tours.

Was it a marker of a past civilization? Not exactly. In the early 1900s, Lehigh University fraternities would use the caverns when it was on public land to haze their new members, who left their mark inside the cave.

The cavern is also home to many geological phenomena, like stalactites and stalagmites, and more you’ve never heard of: flowstone, cave popcorn and cave flowers — the last of which the flap of a bat’s wings is enough to shatter.

“No one knows how it’s formed because it’s so fragile that no tests could be produced,” Garcia said.

Flowstone is naturally white calcite, but decorated with algae and rust. The flowstone “room” of the cavern has been turned into a nonsectarian chapel — the Crystal Chapel — and has held more than 100 weddings.

Patterson explained these formations, attributing them to the abundance of limestone. The rock is easily eroded and eaten away by water that is then reprecipitated, leaving aesthetic formations.

“Water works with carbon dioxide, creating carbonic acid, and then over thousands of years, it creates the passageways in the cavern,” Garcia explained.

Another well-known cave is the Crystal Caves in the farther-away Kutztown, which lays claim to the title of the oldest public-operating cave in Pennsylvania and the fourth-oldest in the country.

“I just encourage people to get out into nature and see it,” part-time owner and president Jim DeLong said. “It’s a limestone cave, so there’s calcite and aragonite crystals that grow in there.”

The cave was discovered in 1871 and was made operational in 1923, bought by DeLong’s grandfather and another gentleman.

“It’s so neat to be down there, to hear the sounds of the cave,” DeLong said.

If you can’t make it to either of these, you can always make your own cave-like geology — just leave some water in your bathtub for around 1,000 years and watch the minerals start to crystallize.

Some geology majors, like Marin Rosser ‘27, said they are quite familiar with the few operating caverns in the area. But others appear unaware of these history-rich formations.

“I didn’t even know there were caves in Pennsylvania,” said environmental science major Madelyn Maina ‘28.