Siberia

Region · Earth · position approximate (fictional or vague in the sources)

Cinematic

1991 On December 16 the Winter Soldier was thawed at a Hydra facility in Siberia and sent to Long Island to kill Howard and Maria Stark and take a supply of Super Soldier Serum. (Winter Soldier, permalink)
2016 He leads the pro-Accords side in the Avengers Civil War, visits the Raft prison, and fights Captain America and the Winter Soldier in Siberia. (Iron Man, permalink)
2016 Rogers refuses the Sokovia Accords, breaks with Tony Stark at the Leipzig-Halle airport, fights Stark in Siberia, and frees allies from the Raft. (Steve Rogers, permalink)
2016 T'Challa joins Stark's team and fights at the Leipzig-Halle airport, then follows Stark to Siberia and learns Zemo framed Barnes. (T'Challa, permalink)
2016 At the Hydra base in Siberia he killed the five sleeping Winter Soldiers and revealed the Stark murder footage, breaking the Avengers apart. (Helmut Zemo, permalink)

Secret Wars Howard, McCord and Peggy Carter deal with an alien ship that landed in Siberia and stop Hydra from taking it. (Howard Stark, permalink)
Fresh Start After Krakoa falls he joins Forge's X-Force in a masked disguise as Tank, then retreats to Siberia. (Colossus, permalink)