Trinidad.
I did a project on the Venezuela side of the Gulf of Paria. The foundation is mud for hundreds of feet. To build mooring dolphins we lowered, without resistance, 9 5/8 casing nearly 300 feet. All that earth eroded from around the Tapuis went somewhere.
Try building facilities for seismic activity on such terrain.
“murphy’s War” was filmed in the area we were working.
Yah, I know that not too far from here there are areas where bedrock is over 500 ft. down. Yeesh.