I'm failing to see what longboats, swords and Mjöllnir (Thor's hammer) have to do with Valhalla.
Valhalla is the enormous hall in Asgard (where the dead go after being taken there by the Valkyries) and Odin ruled over Valhalla.
If the place was called, "Vikings" or "Norse Land" or something else along that line, the previously mentioned logos would work. Odin's weapon was a spear and he rode a Sleipnir (an eight legged horse).
And to think that people used to make fun of me for playing AD&D ... pppsssshhhh
