At one point in Aquaman's History a Meteorite of Kryptonite fell into the sea and subsequently hit Atlantis destroying Thierna Na Oge. Aqua Man, at the Batman's request, started mining Kryptonite just in case Superman went rouge.
The mines took the appearance of a large dome with a large crater, now acting like a trench, around it. Miners live on the outskirts of this and some even inhabit the trenches. There are ladders and draw bridges to provide access to the mine.
