In 2004, Denise Schubert and her husband bought a property in San Antonio. They soon noticed a small hole in the ground where air seemed to blow out, causing nearby weeds to sway. For years, they treated it as a curiosity rather than something to investigate.

In 2022, the couple decided to look into it. With help from archaeologists and students, they began digging and uncovered an Edwards Aquifer cave with multiple chambers. One room was estimated to be two to three times the size of their largest above-ground room, which measured 28 by 30 feet.

The Schuberts took care to preserve the cave and developed an attachment to it. The property also sits near 3,500 acres of nature conservancy land that includes Natural Bridge Caverns.

After some time, the couple decided to sell. Realtor Lorie Largan described the property as offering a backyard version of Natural Bridge Caverns. Once the listing drew media attention, buyer interest was strong. Schubert enjoyed giving tours and sharing the discovery, and she hoped the next owner would value it as much as she had. The property was listed for $875,000, and the sale later went pending.

Texas has many other notable caves beyond this backyard find. Here is a look at several of them.

Cave Without a Name

In 1939, a sinkhole on a ranch near Boerne led to the discovery of a large limestone cavern. Local children climbed down with flashlights and ropes and found a vast chamber with formations. The land belonged to rancher Jim Horn, who saw the cave’s potential and, with neighbors’ help, prepared it for tours by 1940.

A naming contest was held, and a young girl reportedly said the cave was too beautiful to have a name. The owners agreed, and it became known as Cave Without a Name.

The largest chamber, called the Throne Room, features a towering column that resembles a throne. Archaeologists have found animal bones and ancient tools inside, suggesting early humans used the cave thousands of years ago. Its constant temperature of 66 degrees would have made it a practical shelter. The Throne Room’s acoustics have also made it a concert venue, hosting performances from classical ensembles to jazz groups.

Natural Bridge Caverns

Natural Bridge Caverns was discovered on March 27, 1960, by four college students from St. Mary’s University in San Antonio: Preston Nodal, Orion Knox Jr., Al Brandt, and Joe Cantou. They entered a narrow crevice on a ranch owned by the West family and found a large underground chamber with ancient formations.

Clara West, the ranch owner, decided to open the caverns to the public. She and her son Harry built pathways and lighting with care to protect the formations. The caverns remain family-run, now managed by Clara’s grandsons Travis and Brad West. The site has expanded to include adventure tours, ziplining, and a ropes course.

In 2023, explorers found skeletons of two small cats dating to the Ice Age, roughly 11,500 years old. Researchers are using DNA and protein analysis to study possible links to modern feline species. Fossilized paw prints were also found on cave walls and floors. The St. Mary’s Adventure Tour offers visitors a chance to explore undeveloped parts of the cave in the style of the original explorers.

Canyon Lake

Canyon Lake was created in 1964 with the construction of Canyon Dam on the Guadalupe River. It spans more than 8,200 acres with over 80 miles of shoreline. The reservoir became a popular spot for boating and fishing, but it also conceals a network of underwater caves formed over millions of years by limestone erosion.

Divers have explored submerged chambers containing stalactites, flowstone, and fossils of marine life from a prehistoric sea. The caves also support fish and crustaceans adapted to dark environments.

The lake also covers relics of the past. When the dam was built, rising waters submerged small communities, including Rebecca Creek and Hancock. Both towns were abandoned as residents relocated. Remnants such as foundations and roads are rumored to remain visible to divers.

Caverns of Sonora

The Caverns of Sonora, located outside the town of Sonora, formed over millions of years through the dissolution of limestone by acidic water. The caves are known for helictites, delicate crystals that grow in multiple directions. These formations are among the most distinctive in Texas.

The cave was discovered in the early 1900s by ranchers searching for water. Deeper exploration in the 1950s revealed chambers filled with calcite formations. The Mayfield family, who owned the land at the time, opened the caverns to the public in 1960.

One of the most famous formations, the Butterfly, was damaged by visitors before conservation rules were established. Some formations were broken off as souvenirs or accidentally brushed. Today the site follows strict guided-tour rules, and visitors are asked not to touch surfaces in order to protect the formations.

Longhorn Caverns

Longhorn Cavern was carved by an ancient underground river, giving it smooth walls and flowing stone draperies that differ from typical drip-formed caves.

During Prohibition, the cave reportedly became a secret nightclub. Jazz bands played in the chambers, and visitors danced in the cool underground space. The remote location helped conceal illegal activity, and bootleggers are said to have used the site to evade authorities.

After Prohibition ended, the Civilian Conservation Corps worked on the site during the 1930s. They removed debris, built trails, and constructed stone structures that remain part of Longhorn Cavern State Park today. Tours now cover the cave’s geology and its varied history.

Wonder Cave

Wonder Cave in San Marcos was formed about 15 million years ago when the Balcones Fault shifted, cracking the limestone. Unlike caves shaped mainly by water erosion, Wonder Cave owes its structure to tectonic movement. It is one of the few fault-formed caves in the United States.

Mark A. Bevers discovered the cave in the late 1800s. Early visitors were impressed by its features and described it as a wonder, which became its name. The cave contains fossils of ancient sea creatures and jagged formations from the fault line. Visitors can stand directly inside the fault during guided tours. The cave is part of Wonder World Park, which also includes an anti-gravity house, a wildlife park, and a train ride.

Bracken Bat Cave

Bracken Bat Cave near San Antonio hosts the largest colony of bats in the world. Each summer, an estimated 15 to 20 million Mexican free-tailed bats gather there. The bats migrate from Mexico in the spring to raise their young in the cave’s warm interior.

The bats feed on agricultural pests, consuming large quantities of insects each night. This provides natural pest control for farmers and reduces the need for pesticides. The colony also contributes to pollination and seed dispersal in some environments.

In the evenings during summer, the bats emerge from the cave in large swirling groups. The site is managed by Bat Conservation International, which limits public access to reduce disturbance. Guided tours and evening viewing events are offered during the summer months.

Cascade Caverns

Cascade Caverns, near Boerne, formed over millions of years by water moving through limestone. The cave’s name comes from an underground waterfall that remains one of its main features. The sound of falling water echoes through the chambers.

The cave was known to Native Americans and later discovered by settlers in the 1800s. It became Texas’s first private touring cave, with visitors exploring it as early as the 1870s. It officially opened to the public in 1932.

The cave supports wildlife adapted to darkness, including rare salamanders and insects. Its temperature stays near 60 degrees. The Cathedral Room, where the waterfall is visible, has hosted weddings and concerts. Flashlight tours and geology workshops are among the educational offerings.

Inner Space Cavern

Inner Space Cavern near Georgetown remained sealed for thousands of years until it was discovered in the early 1960s by a construction crew building Interstate 35. Drilling equipment broke through into a hollow space, revealing a large cavern in pristine condition.

The cave contained formations such as soda straws, flowstones, and columns. Scientists also found fossils of Ice Age animals, including mammoths, saber-toothed cats, and giant sloths. The cave appears to have acted as a natural trap for animals that entered and could not escape.

Inner Space Cavern opened to the public in 1966. The Discovery Tour offers a standard walk through the main chambers, while the Wild Cave Tour explores undeveloped sections. The cave maintains a constant temperature of 72 degrees. Its formations include rooms such as the Ice Cream Parlor and an underground pool called the Lake of the Moon.

These caves represent a small sample of the underground geology found across Texas. From fault-formed passages to bat colonies, each site reflects a different aspect of the region’s natural history. The backyard cave in San Antonio, with its surprising scale and proximity to a family home, serves as another example of the formations hidden beneath the surface.