View source for Inner Space Cavern

{{short description|Cave in Georgetown, Texas, United States}}
{{Refimprove|date=November 2012}}{{Infobox cave|name=Inner Space Cavern|other_name=Laubach Cave|mapframe=yes|coords={{Coord|30|36|28|N|97|41|16|W|format=dms|display=inline,title|type:landmark_region:US-TX}}|website=https://innerspacecavern.com/}}[[File:Innerspace cavern0700.jpg|thumb|View of the Ice Cream Parlor (First Formation Room), Inner Space Cavern, Georgetown, Texas]]
[[File:Innerspace cavern 0699.jpg|thumb|Drapery Column, Inner Space Cavern, Georgetown, Texas]]
[[Image:Inner space 2005.jpg|thumb|The main entrance to Inner Space Cavern in 2005]]
'''Inner Space Cavern''' (Also known as Laubach Cave) is a [[Solutional cave|karst cave]] located in [[Georgetown, Texas]]. The cavern was formed by [[water]] passing through Edwards [[limestone]]. The cavern is estimated to be around 20–25 million years old but has only been open to the surface since the late [[Pleistocene]] period 14,000–45,000 years ago.

== Geology ==
{{For|details on the region's [[geology]]|Edwards Plateau}}

=== Speleogenesis ===
Inner Space Cavern lies within limestone and dolomite rocks of the [[Edwards Group]] formed during the [[Cretaceous period]].<ref>{{Cite journal|last1=Jasek|first1=James|last2=Russell|first2=William|last3=Lundelius|first3=Dr. Earnest|date=September 1975|title=the Texas Caver|url=https://digital.lib.usf.edu//content/SF/S0/05/50/46/00001/K26-04597-1975-v20-n09.pdf|journal=Texas Caver|volume=20|pages=131–148}}</ref> Following the formation of the [[Balcones Fault]], a series of vertical fractures through the Edwards Formations allowed ground water to freely move through the limestone marking the beginning of the cavern's formation. As water from the surface became ground water, [[carbon dioxide]] (CO<sub>2</sub>) was picked up from the atmosphere and from decaying organic matter, creating [[carbonic acid]] (H<sub>2</sub>CO<sub>3</sub>), which would react with and dissolve the limestone rocks creating voids. Over millions of years these voids grew leaving behind large rooms and passages. 

=== Fossil Record ===
There were several large openings to the caverns during the [[Ice age|Ice Age]], an evidence of several skeletons of prehistoric Ice-Age animals including a baby [[mammoth]], [[Ground sloth|giant sloth]] and the [[Smilodon|saber-toothed tiger]]<ref>{{cite web|url=https://books.google.com/books?id=Gy4EAAAAMBAJ&q=innerspace+and+saber+tooth+tigers&pg=PA12 |date=March 1979 |title=Underground Gourmet - Inner Space Caverns |work=[[Texas Monthly]] |access-date=September 22, 2019}}</ref><ref name=KDH>{{cite web|url=http://kdhnews.com/news/ancient-cave-underneath-highway-in-georgetown-worth-exploring/article_1a1d4824-e9b5-11e3-98c9-001a4bcf6878.html |title=Ancient cave underneath highway in Georgetown worth exploring |last=Rafique |first=Sarah |work=[[Killeen Daily Herald]] |date=June 2, 2014 |url-access=subscription |access-date=September 21, 2019}}</ref> have been found in the cavern; many were trapped in the cavern after they fell through the opening, unable to escape, and others drowned in thick, [[quicksand]]-like mud at the bottom of watering holes. Some filled-in [[sinkhole]]s have been found, including the prehistoric entrance to the cavern. All natural entrances closed approximately 14,000 years ago. 

== Discovery ==
Inner Space Cavern was discovered by the [[Texas Department of Transportation|Texas Highway Department]] drilling team in the spring 1963 during the construction of an overpass for [[Interstate_35_in_Texas#Central_Texas|Interstate 35]].<ref>{{cite web|url=https://www.kxan.com/news/a-look-into-the-dark-depths-of-inner-space-caverns-for-50th-anniversary/1049740597 |title=A look into the dark depths of Inner Space Caverns for 50th anniversary|last=Ricke |first=Claire |date=June 10, 2016 |work=[[KXAN-TV]] |access-date=September 21, 2019}}</ref><ref name="saber-toothed">{{cite web|url=https://www.texasspeleologicalsurvey.org/showcaves/tssinnerspace.php |date=1994 |title=Inner Space Cavern |work=Texas Speleological Survey |access-date=September 21, 2019}}</ref> The cavern was mapped for the first time by the Texas Speleological Association in 1963;<ref name="saber-toothed" /> since then, several miles of the cavern's passage have been surveyed, with many sections of the cavern remaining unexplored, due to filled-in areas being blocked.

== Tourist attraction ==
The cavern was opened to the public in 1966.<ref name="KDH" /> Three different levels of tours are available, ranging from a basic walking guided tour to an advanced wild cave [[Caving|spelunking]] tour, with over 1.2 miles of passage being open to the public. However, non-public passages are well-guarded and independent exploration is not allowed. Apart from the main entrance, which was created by [[dynamite]] blasts, a vertical borehole, located in the Inner Cathedral Room, serves as an emergency entryway/exit and a means for ventilating the cavern.

==References==
{{reflist}}

==External links==
* {{Commons category-inline|Inner Space Cavern (Georgetown, Texas)}}
*[https://innerspacecavern.com/ Inner Space Cavern] official website 
* {{Handbook of Texas|id=rqi01|name=Inner Space Cavern}}

[[Category:Caves of Texas]]
[[Category:Georgetown, Texas]]
[[Category:Landforms of Williamson County, Texas]]
[[Category:Limestone caves]]
[[Category:Show caves in the United States]]
[[Category:Texas Hill Country]]
[[Category:Tourist attractions in Williamson County, Texas]]