Fort Charlotte, Charlotte Street, Lerwick

Fort Charlotte was designed by John Mylne, Master Mason to King Charles II. The original fort was begun in 1665-7, then substantially rebuilt in 1781 after lying in disrepair for almost a century. It comprises roughly pentagonal ramparts with bastions at the corners enclosing a complex of predominantly 18th century buildings, some with later alterations. The structures have lime harled walls and droved sandstone ashlar dressings, with grey slate roofs, cast-iron gutters and downpipes.

The external fort walls are constructed of random rubble with a flagged wallhead. The east wall is battered towards Commercial Street, while the west wall is buttressed on its east side.

The western block is a two-storey, eleven-bay symmetrical barrack block. The east (entrance) elevation features a timber entrance door with a heavy bracketed cornice above it, a blank (rather than window) at first floor level above the door, and regular windows throughout the rest of the block. The left and right ends of the building are stepped forward and higher than the main block. The north and south elevations each have a door at ground floor in the centre with a window above and windowless blank bays flanking it. The west (rear) elevation is a ten-bay near-symmetrical elevation with doorways flanking the centre bay at ground floor level. There are regularly spaced windows at first floor with segmental-arched lintels, and additional doorways at ground floor level in the outer left and right bays, with an additional window inserted to the left of the latter.

The northern block is a two-storey, seven-bay asymmetrical barrack block on a sloping site, comprising a five-bay near-symmetrical building extended to the west by two wider additional bays. It has twelve-pane timber sash and case windows, a grey slate M-shaped roof with harled chimney stacks topped with copes and circular cans. The south (entrance) elevation contains seven bays with a harled stair accessing the first floor in the penultimate bay to the left, where the main door is also located. Regular windows span across the elevation. The east and west elevations have M-shaped gables; the east elevation contains two doors at ground floor level. The north (rear) elevation is asymmetrical, grouped in five and two bays, with the five-bay group symmetrical and featuring a door at first floor in the centre bay, while the two-bay group is blank at ground floor level.

An out-house is constructed as a harl-pointed building with a hipped grey slate roof, notable for a single sixteen-pane timber fixed-light window in the west elevation to the right of centre.

The southern block, serving as an artillery storehouse, is a single-storey eleven-bay building by the south gate, constructed of random rubble and part harled, with timber doors and timber sash and case windows. The roof is hipped grey slate with harled and coped ridge chimney stacks. A rubble store stands adjacent to the west elevation.

A reservoir is a single-storey rubble building with a platform roof with pitches flanking it to the east and west.

The powder magazine comprises a harl-pointed and coped rubble wall enclosing a submerged and flagged courtyard with a shifting room at the southeast corner and magazine at the centre. The shifting room is gabled with two evenly spaced square windows in the west elevation and a door in the centre of its north elevation. The gabled magazine has slit windows in the middle of each elevation and doors on the south elevation.

The scheduled monument designation (SM90145) is recorded separately and is excluded from this listing.