Helheim
General Information
Helheim is the Norse Underworld which features in the plot, mythology and final level of Tomb Raider Underworld. Lara Croft discovers it on the bottom of the Arctic Sea, after following Jacqueline Natla's coordinates.
Helheim itself is situated at the point where the supercontinent Pangea first split, over 170 Million years ago. As such, it claims to be the weakest point on the planet - Earth's Achilles Heel. The Jőrmungandr Mechanism is housed in Helheim for this very reason; poised over Earth's weak-spot, ready to re-open the tectonic plates and cause global cataclysms from earthquakes and active volcanoes.
The Jőrmungandr Mechanism spawned myths of the Norse Ragnarok, as Jőrmungandr itself was (in the mythology of Tomb Raider Underworld) the ridges of tectonic plates which encircled the Earth on the ocean floor.
According to Natla, Helheim is another name for 'Avalon'.
Builders and Architecture
Helheim's exterior features many staircases, indicating that when it was built, it was above sea-level. The main entrance is located within the Helheim Fortress, at the end of a submerged road on the Arctic Seabed, dubbed the 'Helheim Highway'. The highway is flanked on either side by gigantic statues of Norse Warriors, which act as a locking device for a drawbridge that covers the entrance to the Fortress.
Inside the fortress is a labyrinth of corridors, each leading off in a different direction to form a city complex within the fortress. One corridor leads to the actual gateway to Helheim, and to the Jőrmungandr Mechanism. The Goddess Hel was said to preside over this realm - a fearsome being, half-female and half-skeleton in appearence. Her image appears on the gateway to Helheim.
The origin of Helheim and the Jőrmungandr Mechanism are unknown, although according to Tomb Raider Underworld both were built and created by the Ancients. A date of their creation is not given, although it must have been within the last 200 Million years.
The structural architecture within Helheim is remarkably similar to that of Atlantis, suggesting that both were built by the same race and possibly even by the same culture. The internal corridors are covered in rows of ancient and arcane glowing glyphs. All Daises seem to connect to Helheim, suggesting that they were also built by the same civilisation.