Number 3 Store (Mo 66)

No. 3 Store, also known as MO 66, is a storehouse located in Morice Yard, Devonport, built between 1840 and 1855, with alterations made in the mid-20th century. The structure is made of squared coursed limestone with granite dressings and features a hipped slate roof.

The building is two storeys high and has a nine-window range. It has symmetrical sides with a first-floor cill band. The central entrance is segmental-arched and features 20th-century doors, with a matching tripartite window above it. The ground-floor windows are round-arched, while the first-floor windows are flat-arched, all fitted with 919-pane sashes. The west side has two wide round-arched doorways with timber doors and a tripartite fanlight, situated beneath a single segmental-arched tripartite sash. On the north side, the ground-floor windows are partially bricked up, and there is a spiral 19th-century iron fire escape at the end.

Inside, the store contains inserted partitions and stairs on the ground floor, while the first floor remains open with a ceiled roof. Some old spar timbers have been used as floor ties.

Historically, the Yard was established in 1720 by Colonel Lilly for the Board of Ordnance and expanded in the 1770s. This storehouse is one of the last buildings constructed by the Board of Ordnance and is paired with No. 6 Store, Sail Loft. It is a late addition to the site, which is recognized as one of the best surviving naval ordnance yards in the country.