The Hall of Armor was an alcove in Tony’s basement workshop(above his wine cellar) where he displayed his Iron Man armors. Tony constructed the Hall of Armor after the events of Iron Man and initially featured a reconstructed MARK I, MARK II, the still battle damaged Mark III and the Tony’s current suit, the MARK IV. During Tony’s birthday party, Rhodey took the MARK II from the Hall of Armor and took the suit to the Air Force after a brief skirmish with Tony who was wearing the Mark IV.
Tony likely updated the Hall of Armor after the events of Iron Man 2 to feature the reconstructed MARK I, the reclaimed MARK II, the battle damaged Mark III, the retired MARK IV, the restored MARK V and Tony’s current suit the MARK VI. While this version of the Hall of Armor is never shown on screen, it makes logical sense that Tony would upgrade the Hall of Armors to include his new suits.
The final Hall of Armor featured the reconstructed MARK I, the reclaimed MARK II, the battle damaged Mark III, the retired MARK IV, the restored MARK V, repaired MARK VI and MARK VII and an extension to the Hall that was located below the wine cellar(which was located underneath Tony’s basement workshop) where Tony housed the Iron Legion(MARK VIII-MARK XLI). This extension to the Hall was accessed through the platform in the center of the Hall of Armor and lowered through the wine cellar while an iris opened below and allowed the platform to continue down into the Hall of Armor extension.
The Hall of Armor was destroyed during the Destruction of Tony Stark’s Mansion. The extension to the Hall of Armor remained intact although large pieces of debris were covering the iris making it impossible for it to open. Once the debris was cleared, Tony initiated the House Party Protocol and the Iron Legion made their way to Miami to fight in the Battle on the Norco. Following the battle, Tony initiates the Clean Slate Protocol destroying the armors that survived the battle. The wine cellar and Hall of Armor extension are both destroyed following the complete demolition of his mansion, as seen at the end of Iron Man 3 when Tony throws his old RT into the ocean at Malibu Point.