Kvorns
From superman.nu: Supermanica
The name given to a mysterious ancient race of Kryptonians. The Kvorn were the original rulers of the city of Kandor.
In October 1967, Lois Lane and Lana Lang discover the remnants of the Kvorn civilization beneath the city of Kandor. While pursuing the Sky Thief, the duo find themselves in "the Caves of Kandor, a maze of tunnels bored by the ancient Kvorn," and accessible only through "a vast submarine cavern" directly beneath Kandor's Aqua-Zoo. The Caves are decorated by hieroglyphics, carvings, and hidden passages which lead to "an ancient Kvornian treasure." The "savage" Kvornians were also noted for their magnetic "Jewel-Masks" (SGLL No. 78: "Courtship, Kryptonian Style!").