Iron Mountain is the portal hub beneath Gary, Indiana: a spherical chamber where six main portals anchor six epochs, each sealed to an eclipse.
The six main portals lead to 428 (Uchronic Mediterranean), 1494 (the Terra Sequence, mythic plane), 1919 (Siberia), 1987 (Gary, Indiana), 2227 (Tana del Lupo, Italy) and Imperia Alta Ra (cosmic plane).
Six more are marked in sky-blue: 1788 (the Two Cities), 1300 (Florenzen), 1665 London (Annus Mirabilis), 1889 Paris (the Regulators), 1887/1888 (the Deep Ones) and 2087 (the Pandemic of the New World).