Above ground are buttressed arcades in nine bays with corbelled parapets and gargoyles. Older building roofing systems generally comprise the roof, parapets and cornices. The roof is hipped with Welsh slate behind balustraded parapets. It resembles a medieval castle with crenelated parapets and towers. The parapets of the walls are surmounted by urns. Carved parapets, as well as gables with dormers, run along the copper roof. Its architectural decorations included towers, turrets, and ported parapets. Above the portico is a large balcony with stone parapets overlooking the courtyard. He called on the camp guards who were standing on the parapets of the rampart. Parapets surrounding roofs are common in London. It has three turrets with crenallated parapets. The roof had gunports in the parapets. It was modified in the 20th century, when parapets and railings were added. It is designed without handrails, using stainless steel parapets instead. Bands of vertically set stones project below the parapets on the towers.