On the northwest lawn of the 'Iolani Palace grounds sits the castle-like 'Iolani Barracks.

'Iolani Barracks was originally built in 1870-71 on the land where the Hawaii State Capitol building now sits. It was designed to house the royal palace and royal tomb guards. German architect Theodore Hececk designed the Barracks as well as the new Royal Mausoleum in Nu`uanu Valley off of the Pali Highway. The building is made of coral blocks and intended to look like a medieval castle.

When constructed 'Iolani Barracks contained a kitchen, mess hall, dispensary, living quarters and prison lockup. Following the overthrow of the Hawaiian monarchy in 1893, the Royal Guard was disbanded. 'Iolani Barracks was then used for different purposes at different times, including use as headquarters for the National Guard of Hawaii, a temporary shelter for refugees of the 1899 Chinatown fire, a government office building, and even a storage facility.

When plans were completed to construct the State Capitol Building, it was decided to move the Barracks to its present location on the grounds of 'Iolani Palace. The building was dismantled block by block and reconstructed in 1965.

'Iolani Barracks now houses The Palace Gift Shop, ticket office, video theatre, and membership office.