12 Reviews
Hello everyone! This is a friendly reminder that any of these fun places we may visit, we are a guest at. Please treat both businesses and trails with the utmost respect. We here at Hidden San Diego follow the 'Leave no Trace' mantra, meaning whatever you bring with you comes back with you. If you see trash on a trail, please do your part to help remove it. Remember, we are not picking up trash from another person but instead cleaning up for Mother Nature. Happy adventures!
THIS SPOT IS PART OF OUR MEMBERSÂ SECTION
Dog-Friendly: n/a  Kid-Friendly: n/a
**No Trespassing Zone**
There is not much information about this cave on the internet, but the information I could dig up is extremely interesting. Apparently this was a cave first that later was used for mining. It is quite possible that it was used for shelter at some points. It was filled in with concrete by the city in the 80’s but used to go extremely far in. I did find this off of the internet though.
“Beginning in 1873, granite mines appeared in Mission Gorge. Light gray in color, the granodioritic rock extracted from these mines was used to construct roads, buildings, jetties, and dams. Blocks of granite from the Gorge were used in the construction of a breakwater in San Diego Bay and are still in place today. The family of Robert Waterman, Governor of California from 1887 to 1891, built the San Diego and Cuyamaca Eastern Railroad, which allowed the granite to be shipped economically from the mines.
Modern mining industries, which provide sand, gravel, and decomposed granite products, evolved out of the early granite mining business. Many firms extracted sand and gravel on lands now part of Mission Trails Regional Park, including J.B. Stringfellow, the Kenneth Golden Company, H.G. Fenton, and the V.R. Dennis Company.
In addition, the Morse Construction Company operated a dynamite magazine on park premises in the 1960s. Kumeyaay Lake and other nearby ponds are the by-products of these mining operations, created by the removal of rock materials in the late 1940s.”
This area is filled with quartz, mica and black tourmaline. It is truly beautiful. The caves are nothing more than holes in rocks these days. They are interesting from the outside but there’s not much to explore inside. The cave used to be quite extensive back in the day though, large enough to go water-tubing in, with stalagmites growing inside! The main mine we saw was filled with water so this is definitely possible! According to one of the local historians, there were two bodies that were found in this cave–one person got lost inside and the other murdered. This may have contributed to why it was filled in.
Personal Experience: Finally finding this spot was quite a feat for us! This was our second attempt looking for them. The first tip took us deep in a canyon with nothing but nature around us. A month later, after a much better tip, we headed out again and this time successfully found the mines! We had a very nice hike–although we went in early spring when the weather is mild. We passed a pond with a mini-waterfall. This area alone was pleasant enough to spend some time at. Would have been nice for a picnic. After a small hike up a hill we stumbled upon the mines! Both have been filled so there is not too much to see but there are crystals everywhere!
Anonymous
Wow, you found it! The waterfall/rocky area is right next to the dirt road. The neighborhood kids talked about going there in the 1970s and 1980s. All kinds of crazy stuff happened back there by Grossmont college.
April 17, 2014
Jon
Found the small one today but could not locate the one with the larger opening. Which direction is it from the first one?
January 17, 2016
Anonymous
Where exactly is this place?
January 18, 2016
Norrie Robbins
I’m working on sediment deposition behind Old Mission Dam. Is this site upstream or downstream of Old Mission Dam?
March 15, 2016
Ernie Bornheimer
Sorry, the east side.
May 5, 2016
Ernie Bornheimer
Some time in the late 60s or early 70s my cousin took me to the entrance of one of these, but we didn’t go in. My recollection is that it was on the west side of Cowles. There was a flat empty area in front of the cave entrance. I’d like to know where it is exactly, please reply if you know……thanks!
May 5, 2016
loren wilson
according to legend,this is where the Indians found gold.ive been there many times,lot of inclusions,some nice crystals.gold could be where you find it.
September 22, 2016
Anonymous
crawled in the first one. low crouch one. tight fit but opened up to walking room, and branched off a little to another small chamber. never did find the one with the big opening? this was around 1958 and we were all around 10 years old, or would not have fit through the opening…
June 25, 2017
Anonymous
Just went up today. Super fun to be walking on so much quartz and other crystals. I have never seen so many ever! Super easy hike and had a great time looking for shinny minerals.
September 15, 2017
Tim Arnold
I grew up just above the canyon where Crystal Cave existed. Back in 1968-1976 it was boarded up with a very substantial barricade to keep kids out since everyone my age (12 at the time) knew where this cave was. The story I heard was that the crystalline rock mined from the cave was used in the production of old-timer crystal radio sets around the turn of the century that didn’t need battery or ac power. ???WTF!
November 22, 2017
Anonymous
I wonder how spray painted this is nowadays, after being published here.
June 1, 2020
San Carlos Local
They called it Crystal Caves. You would crawl in, then it would open up inside, where you could swim around, and the roof of the cave was filled with crystals. Dad took me here about 15 years ago, still remember how but there isn’t much to see now. Small opening like in the picture.
June 29, 2022