North Pole
From superman.nu: Supermanica
The most northern point on the surface of the Earth.
In May/June 1948, Superman encounters and defeats several actors masquerading as the Norse gods Thor, Loki, and Odin on the set of a film being produced at the North Pole (S No. 52).
In November 1972, Superman battles the Galactic Golem near the Fortress of Solitude. Forcing the Golem over the magnetic North Pole (the point on the Earth's surface where the planet's magnetic field is strongest) Superman encases him in molten iron and nickel from the Earth's core, which are heavily attracted by magnetism. (S No.258/1: "Fury of the Energy-Eater!").