Alfred Keller's 1908 courthouse on Riemergasse sat at the heart of Vienna's Innere Stadt for over a century before London-based studio Goddard Littlefair transformed it into the Mandarin Oriental, Vienna, which opened in 2025. The building's Secessionist credentials are unmistakable from the street: a heavily rusticated limestone facade, ornate plasterwork friezes running between floors, and tall multipaned windows that give the composition its civic gravitas. Working within Vienna's UNESCO World Heritage-listed Ringstrasse precinct imposed strict preservation obligations, and Goddard Littlefair met them honestly, retaining original stonework and stucco throughout while threading 138 keys across four floors. The interiors translate the building's Secessionist spirit into a palette that feels warm without heaviness. Guestrooms pair oak-framed headboards with creamy upholstered panels, dark herringbone parquet, and arched plaster molding that echoes the facade's geometry; the effect is of a private Viennese apartment assembled with particular care. The glass-roofed central courtyard restaurant carries the period atmosphere furthest, its coffered plasterwork ceiling, sculptural ironwork room dividers, and graphic black-and-cream upholstered chairs evoking fin-de-siècle Vienna at its most confident. Below ground, the spa pool room is finished in dramatically veined dark marble with brass-detailed archways and a golden ceiling recess that casts the water in amber light. It is a property that earns its setting by understanding exactly what the building has always been.