Hôtel d'Hallwyll, Private mansion in Quartier Sainte-Avoye, Paris, France.

The Hôtel d'Hallwyll is a private residence on rue Michel-le-Comte featuring Italian Renaissance architecture with balanced facades and Doric column galleries surrounding a central garden courtyard. Inside you find an original staircase and garden decoration elements that are partly visible from the street level.

Built in the early 18th century for the widow of Louis de La Palu, Count of Bouligneux, the mansion was leased from 1757 to 1766 to the Thelusson & Necker bank; Jacques Necker lived there and his daughter Germaine, later Madame de Staël, was born in 1766. Marie Thérèse Nicole Demydorge and her husband François Joseph d'Hallwyl then had Claude-Nicolas Ledoux remodel it, the only surviving example of his Parisian domestic architecture.

The building is a private residence and cannot be visited inside; its courtyard door at no. 28 and the garden entrance at no. 17 bis of rue de Montmorency are the only points a passer-by can approach. The name comes from Marie Thérèse Nicole Demydorge, who inherited it and married François Joseph d'Hallwyl, colonel of the Swiss Guard regiment.

The building offers exterior views from rue Michel-le-Comte and rue de Montmorency where you can see the facades and rooflines. Since it remains a private residence, access to the interior is limited, but the street views provide a clear sense of the architectural design.

Ledoux's garden design at the Hôtel d'Hallwyll prefigured the Saline royale d'Arc-et-Senans: an atrium ringed by Doric colonnades, with two overturned urns pouring torrents of water around a niche holding a Grace. A painted trompe-l'œil decor covered the blind wall of the Carmelite convent facing rue de Montmorency. The garden door opens at 17 bis, rue de Montmorency.