Agricola Tower

This is a late 12th/early 13th century gate-tower, forming part of Chester Castle's Inner Bailey. It was altered after 1302 and refaced in 1818 by Thomas Harrison, with further repairs in 1923 and 1952. The tower is constructed of bunter sandstone ashlar, topped with a metal roof. It is three storeys high.

The south-western front features a central, pointed gate arch with stepped reveals and voussoirs, now glazed. Projecting turrets flank the arch, with a clasping buttress to the left, shared with other corners. Both turrets retain some stonework pre-dating 1818. A later gabled abutment is visible on the tower. Above the lower stage is an offset. A pointed lancet window with voussoirs and an iron grille is located on the first floor. A rectangular window is visible in the right-hand staircase turret. A battlemented parapet features chamfered coping. A 19th-century single-storey provost block adjoins the left side, but is not included in the listed building. The right-hand reveal features a projecting staircase turret with a blocked light. A central square window is on the second floor. The left reveal is blind and was entirely refaced in 1818.

At the rear, projecting buttresses are located to the left and right of centre. A blocked arch is set within a recessed central wall. A rectangular ground floor window is present, alongside a first floor lancet window to the chapel and a blocked window on the second floor.

Internally, the ground floor passageway was altered following a fire in 1302. A sexpartite vault with chamfered ribs rests on chamfered attached pillars, which have simple chamfered abacus capitals and bases, supported on a raised plinth. A pointed arch leads to the stair turret on the south-eastern wall. The first floor contains the Chapel of St Mary de Castro. Three round wall pillars with moulded bases and water leaf capitals support two quadripartite vaults with keel-moulded ribs. A pointed arch defines the altar recess on the north-eastern wall, with an aumbry to the right of it. A pointed door arch with a keel-moulded surround sits within a projecting portion of the wall on the south-eastern side.