Part of Pyestock Cell 3 jet engine testing area, located underground to minimise noise pollution.
I have since learned that the circular ribbed thing beyond me would have had a cooled liquid circulating through it, its purpose was to cool the hot vapours blasting through here as they passed through the wind tunnel and the engine testing area. The rods protruding from the floor were inhibitor torches, kind of like large bunsen burners. Their job was to ignite any remaining fuel particles that did not get ignited within the engine and so stopping 'potentially explosive' chemicals building up further down the cell.
Reminds me visually of the scene at the end of Matrix Revolutions where Neo goes to the Machine City and speaks with the head AI robot.
Click the image to enlarge.
A composite made with bits of 16 different exposures.