The Armory is a museum that focuses on Trøndelag's defense history, from Viking Age battles to the two world wars. The museum offers visitors an honest portrayal of the region's military past through a collection of weapons, uniforms and historical artefacts. One of the central parts of the museum is the Rustkammeret, which was founded in 1826 under the name "Den historische armoury".
The museum is located in Erkebispegården, a building that has been used for defense purposes for over 300 years. The exhibitions provide an insight into both local and national military history, and guided tours are also offered to other military historical sites in central Norway. The Armory thus acts as an important resource for those who wish to learn more about the region's military heritage.