Inner Space Cavern (Laubach Cave)

Laubach is the name on the plaque and the name paleontologists still use. The Texas Speleological Survey says the Georgetown Corporation formed in 1964 and leased the cave from the Laubach family, who kept the right to use it. The mapped passages run under Interstate 35 and measure about 20,000 feet. The plaque's 100 million years fits the Cretaceous Edwards limestone, but Wikipedia puts the cavern itself at 12 to 25 million years old. The same survey page notes that clear floodwater sometimes closes part of the trail for months.

What the plaque says

Inner Space Cavern (Laubach Cave) Discovered in 1963 on land of W. W. Laubach by core-drilling team, Texas Highway Department. Exploration begain in November 1963 and continues to present. Carved by water from Edwards limestone, cave lies along the Balcones Fault and is estimated to be 100 million years old. 95 percent of formations are still growing. Cave was apparently open during late Pleistocene (20,000 - 45,000 years ago), for bones of many extinct mammals have been found in debris cones filling former natural entrances. Remains of sabre-toothed cats and mammoths are represented. (1973)

Where it stands

Worth the stop nearby

• Inner Space Cavern — steps away
  A Georgetown cave found in 1963 when highway engineers drilled test holes, holding Pleistocene fossils and 72-degree rooms that visitors reach by an artificial tunnel.
• Williamson County Courthouse — 2.1 mi
  The fifth Williamson County courthouse, a Beaux Arts building by C. H. Page, rises over a Georgetown square of more than 50 Victorian-era buildings.
• The Round Rock — 6.6 mi
  A table-shaped stone in Brushy Creek gave Round Rock its name in 1854; the Chisholm Trail crossed the creek near it, and Old Town stayed behind when the railroad pulled the town east.
• Mount Bonnell — 20 mi
  Austin's old lookout over the Colorado, named by an 1838 traveler, picnicked on by George and Libbie Custer, and reached by a 1939 flight of about 100 limestone steps.

More markers nearby

• Dalrymple, William Cornelius — 1.4 mi
• St. John's United Methodist Church — 1.9 mi
• Negro Fine Arts School — 1.9 mi
• Jessie Daniel Ames — 2.0 mi