I'm reading a novel called the Great White Space.
Dated 1974 it was penned by Basil Copper.
My paperback was published by Sphere.
Its a story about the exploration of an underground realm but the remarkable thing is the number of similarities with the film Prometheus.
In The Great White Space the intrepid explorers come across colossal doorways and caverns covered in strange hieroglyphics.
They stumble across vast arrays of huge vases, which contain inhuman creatures held in oozing liquid and there is speculation about the architects of the caverns, who they call among other things engineers!
The cover of another edition of the book hints at the huge doorways hewn through cavern walls by unknown architects.
Have you read the Great White Space readers?