Bodlondeb Castle, including front steps and walls, and former Caersalem Chapel to rear

Bodlondeb Castle is a Gothic villa dating from the 18th century. It is constructed of snecked rock-faced stone with bathstone banding and dressings, and has slate roofs. The front elevation, facing southeast, has four bays, including a semi-octagonal corner bay at the southwest end. The three northeast bays have an embattled parapet which steps up over the centre bay, forming a gable. The centre bay features a narrow sash window without glazing bars in the attic storey, a canted three-light bay window with a stone canopy on the first floor, and a doorway with a pointed moulded head and semi-octagonal buttresses on the ground floor. A double flight of stone steps, with a stone walled balustrade, leads from Church Walks to a landing in front of the doorway. The garden wall along Church Walks is constructed of stone piers. Flanking bays have sash windows with moulded architraves on the first floor and paired sash windows on the ground floor. The semi-octagonal corner bay has large sash windows on the first and ground floors, and small sash windows in the attic. Above the attic windows are blind arrow loops, mock machicolation, a cornice with gargoyles, and an embattled parapet. The southwest elevation has six bays; the third bay is a wide projection with a gable over the attic window and a storeyed bow window to the first and ground floors. The northeast side elevation has two crow-stepped gables, with a further crow-stepped gable to a rear three-window wing.

To the northwest of the main house stands a further wing facing Llwynon Gardens, which was formerly the Caer Salem Chapel. This two-storey structure has stone rubble walls and a hipped slate roof. The northwest elevation has two storeys and three bays with modern transomed casements. There is a gabled, blocked doorway with a plaque recording William Morris Hughes in the gable.

The interior is said to retain a first-floor landing above the present lounge, in the form of a loggia of seven bays, with a marble balustrade and segmental headed arches supported on marble columns with ornate capitals. A staircase with turned marble balusters leads down to a large ground-floor chamber or lounge, which features a fireplace with a canopy and a coffered ceiling with a large glazed light in the centre. Stained glass is incorporated into the upper lights of windows in the Drawing Room, Dining Room, and one bedroom.