Admiralty Arch, First Sea Lord's Residence and Offices, Balustrades and Steps

Admiralty Arch is an official residence and office block that includes a triumphal arch, built between 1906 and 1911 by Sir Aston Webb. It serves as the entrance to the ceremonial approach to Buckingham Palace and is part of the national monument dedicated to Queen Victoria. The building is constructed from Portland stone and features slate roofs. Its design is influenced by late Roman Baroque and reflects Webb's interpretation of Edwardian Mannerist Classicism.

The structure has concave elevations facing the Mall and the area towards Trafalgar Square, cleverly masking the necessary change in axis. It consists of two storeys, an attic storey, a dormered mansard, and a basement, although the southwest office wing has three storeys within a two-storey height. The central triumphal arch is topped with a massive blind crowning attic.

Flanking the 11-window wide central section are two wings, each six windows wide, which feature banded rusticated triple carriage archways. The pedestrian archways are located at the advanced end bays of the central section. The triumphal arch is adorned with engaged modified Corinthian giant columns, while the wings have a similar giant pilaster order. The main floor has architraved glazing bar sashes with segmental heads beneath enriched cornices.

A continuous main entablature runs beneath the channelled attic storey, topped with a balustraded parapet and a blind attic on the central section, which features a bronze inscription and is finished with a cornice and blocking course. The single bay return ends of the wings facing the Mall are channelled and pedimented, with sculpted seated figures at the base of panels that include a cartouche of arms. Ornamental bronze gates are present at the carriage archways, and there is a stone balustrade between panelled dies leading to basement areas, featuring curving arms and shallow flights of steps that define the "rond point" forecourt on the Mall side.