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Buried Treasure cavern Sir Franciss Drake Greenbrae Larkspur San Quentin Plate of Brass

While searching for a safe place to bury the treasure, Drake's men discovered the entrance to a natural cavern along Greenbrae Ridge. Water from a nearby spring pooled in this deep cavern that was used by the Miwok as a source of water during the long dry season. The entrance to the cavern was set-back just far enough from the edge of the ridge so that it could not be seen from the deck of a ship. This made for an ideal spot to hide the treasure and Drake's men redirected the spring's runoff through a cement structure that was an integral part of the tricks designed to scare off or kill any treasure hunters who found the location. 

Drake knew that precious stones would be destroyed by a lack of moisture, so a system was needed to redirect the spring's runoff to create a moist environment in the areas where treasure was going to be buried. An ancient type of valve system, similar to that used in Roman aqueducts was created from a cement-like material. Cannon barrels salvaged from the disassembled ships were placed end-to-end and served as water pipes connecting the valve system to the desired locations. 


Once the pool of water had drained from the cavern, the valuable items were placed inside along with layer-upon-layer of colored clay until the cavern was completely filled. Then, the entrance was covered with several feet of dirt so that it would not be noticed by anyone who came upon The Treasure Site. 

After the task of loading the caverns was completed, the course of the spring's runoff was redirected into the valve and water-pipe system. The heavily-clayed soil would retain moisture during the annual dry season and even through long periods of drought. THE TREASURE WAS NOW SAFE! 

 Alluvial Stones

Alluviua treasure sir Francis Drake Landing site San QUentin Larkspur Greenbrae

 The Emerald Goddess - Umina

artifact treasure Drake Umina the Emerald Godess looted Hanff von der porten crime plate of brass

The Emerald Goddess holds a place on the list of Great Missing Emeralds. It disappeared during the Spanish Conquest of the Incas in Peru during the 16th Century...and was never seen again...until now! Note the features of the face including; the eye, nose, mouth and Inca-style earring. The Goddess also sports two breasts below her face on the torso.

 Smiling/Frowning Ghost Image in the Cavern Wall

drakes treasure ghosts buried cavern san quentin crime true adventure

Images such as the ghost served as maps or markers. In order to confuse the Spanish or anybody else trying to recover the treasure, Drake used several types of reversals when preparing his maps and markers. Misinterpretation of the reversals could be serious or fatal.


The least problematic result of not understanding the reversals was the wasted time and effort of digging in the wrong direction. The more serious outcome could result in injury or even death if the treasure hunter found himself digging in a location that could trigger a deadly trick such as a falling boulder or collapsing room!

Drakes Treasure toxic colored clays buried poison

Layer upon layer of beautiful, but highly toxic

colored clays were used to fill the Treasure Cavern.

This required many layers of protective

clothing to prevent toxic metal poisoning.

Robert Stupack discoverer adventurer writer Drakes Treasure Plate of Brass
Robert Stupack toxic clay discoverer adventurer writer book San QUentin
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