in-situ sculpture
An ornamental or commemorative carving out of rock naturally existing on the site.
Pictured: Crazy Horse Memorial
An in-situ sculpture is not a true structure, but a carving formed out of existing rock which was not moved from its natural site in the carving.
The rock remains at its natural location while the carving gives it the artistic form. The material has not been moved to the site as part of constructing the work.
A freestanding statue or sculpture has a different construction and placement history. Here the artistic work transforms rock already fixed to the place.