The Famous and Most Dangerous Swimming Spot in Texas

It looks like a perfect swimming hole—crystal clear blue water, inviting depths, families gathered along limestone cliffs.

Jacob’s Well is an infamous spring located in Central Texas just outside Wimberley.

While it may look like a giant puddle at a glance, it’s actually the mouth of an underwater cave system that can take daring divers more than 130 feet below the surface.

At least 12 people have died trying to dive or swim in Jacob’s Well, making it one of the deadliest dive sites in the world.

What Exactly Is Jacob’s Well?

Jacob’s Well is what’s known as a karstic spring: one that’s found at the end of an underground cave system, making it a prime opening to enter these underwater caves.

The well is 12 feet in diameter and plunges 140 feet at its deepest point—14 stories underground, underwater.

There are two tunnels: Tunnel A is 4,300 feet long (three-quarters of a mile), and Tunnel B is 1,300 feet long, with the round trip to the terminus of Tunnel A taking five hours.

The water stays at a constant 68°F year-round, fed by the Trinity Aquifer that supplies the spring with water under pressure.

Why It’s Called a ‘Black Hole’

A particularly interesting feature of the cave is called the “Birth Canal.”

It’s a two-foot square portal found at the rear of a fairly large underwater room 75 feet from the surface, situated at the top of a long, steep, gravel-floored slope which is notoriously unstable.

Disturbing the silt creates instant zero visibility—divers describe not being able to see their hand in front of their face. In that darkness, disorientation sets in immediately.

Which way is up? Where’s the exit? The narrow passages branch off in multiple directions, creating false exits that trap panicked divers.

“This is the horror story side of it,” says Don Dibble, a dive shop owner with more than 40 years of diving experience. “Jacob’s Well definitely has a national reputation of being one of the most dangerous places to dive.”

Even experienced cave divers have died here, underestimating the complexity below or encountering equipment failures in tight spaces where there’s no room for error.

The Deaths

Two young Texas men were caught in one of the well’s caves and drowned in 1979, another diver’s remains were flushed out of the well in 1981, and there have been other fatalities until 2000.

Kent Maupin, a 20-year-old experienced diver and assistant instructor who worked at a Pasadena dive shop, knew that over the years, four divers had drowned in the section of the well he wanted to explore.

He and Mark Brashier, a 21-year-old student, died on September 9, 1979, while attempting to explore the deepest chambers.

A recovery effort lasting twelve days was called off when it became clear the best thing to do was to leave the bodies where they were and seal the well off.

Maupin’s body wasn’t recovered until twenty years later during a mapping expedition.

Current Status: Viewing Only

Swimming at Jacob’s Well Natural Area is canceled for the foreseeable future due to low water levels, with swimming not permitted since June 2022 due to unsafe water conditions.

Jacob’s Well has remained near or at zero flow for about two years, with factors affecting the deteriorated flow including multi-year drought and resulting increased demand on the Trinity Aquifer.

This marks only the sixth time in recorded history that the spring has stopped flowing.

The Natural Area is currently open to the public during regular hours from 8 AM to 6 PM, though swimming and water access are not permitted.

Jacob’s Well Natural Area offers approximately 3 miles of hiking trails, with hiking free to the public and no reservations needed.

Free public guided tours are offered each Saturday from fall through spring from 10 AM to 11 AM, and Nature Center exhibits are open Saturdays and Sundays from 10 AM to 3 PM.

Respect the Danger

Jacob’s Well represents nature’s duality: inviting and deadly, beautiful and dangerous, popular and protected.

Local rescue divers put a covering over the hole in an attempt to prevent more fatalities, but adrenaline seekers pulled it off and left a note stating, “You can’t keep us out”.

You can only dive into Jacob’s Well today if you have a special permit from the County stating you are an expert, though swimming (when permitted) remains perfectly safe if you stay on the surface and follow all posted rules.

Nine to twelve people learned the hard way why Jacob’s Well earned its deadly reputation.

You don’t have to.

Experience the beauty from the viewing platform, hike the trails, enjoy the Hill Country scenery—but leave the deep diving to your imagination. This Texas treasure is worth seeing, just not worth dying for.