Rector's Palace, Dubrovnik

Where it sits. The Rector's Palace stands on Pred Dvorom, the short open space between Luža Square and the cathedral, on the seaward side of Dubrovnik's old town. It is a low, wide building of pale limestone with a six-arched portico along its front, and it was for four and a half centuries the working heart of the Republic of Ragusa: council chambers upstairs, the rector's apartment on the piano nobile, the state armoury, the treasury, a powder magazine and the town prison all under one roof. The scale is domestic rather than imperial, which was the point — Ragusa advertised itself as a republic of merchants, not a court.

Built twice, by accident. The gunpowder stored in the earlier castellum exploded in 1435 and destroyed it. The Neapolitan engineer Onofrio della Cava, then in the city building its aqueduct, produced the Gothic replacement. In 1463 the powder blew up again, wrecking the new building; the Florentine Michelozzo Michelozzi submitted a Renaissance design that the conservative Senate found too radical, and the reconstruction was carried out instead by Salvi di Michele of Florence, working from the surviving Gothic frame. The earthquake of 1667 brought further damage and Baroque repairs, so the fabric is a legible sandwich of three periods. The portico capitals survive from the fifteenth-century campaign, including the famous Aesculapius capital, which shows the ancient physician in a cluttered workshop among his jars and instruments — one of the earliest depictions of a pharmacy in European sculpture, and a nod to a city that ran a public pharmacy from 1317.

How the Republic worked. The rector was elected for a single month, had to be at least fifty, and during his term lived in the palace and could not leave it except on official business. Power was spread so thinly that no individual could accumulate it. Carved above the door to the Great Council hall is the instruction the Republic gave every man who entered: Obliti privatorum publica curate — forget private affairs, attend to public ones. In the atrium stands the bronze figure of Miho Pracat, a shipowner from the island of Lopud who left his considerable fortune to the state and became, in 1638, the only commoner the Republic ever honoured with a statue.

On screen. In the second season of Game of Thrones this atrium and its arcaded staircase became the residence of the Spice King in Qarth — the merchant prince Daenerys petitions for ships and men, and who turns her down flat. The production used the courtyard almost as found: the double-height arcade, the open staircase and the pale stone needed only hanging fabrics, plants and a change of light to read as a wealthy trading city on the far side of the world. Qarth as a whole was assembled from several Croatian sites rather than one place — the garden scenes were shot on Lokrum, the exterior of the House of the Undying is the Minčeta tower on the city walls — so no single location can be pointed at as the city. Interiors of the Spice King's house beyond the courtyard were set builds.

What you actually see today. The palace is now the Cultural History Museum, part of the Dubrovnik Museums group, and it is a genuinely good one. The ground floor keeps the courtroom and the barred cells, with the original locks; upstairs, period rooms hold Ragusan furniture, portraits of rectors, coins struck by the Republic, and the sedan chairs and state coach. Look for the set of keys and the three-lock system by which the treasury could only be opened when three separate officials were present. The atrium is used for concerts through the summer, and its acoustics under the vault are excellent.

Getting there and timing. From Stradun, walk to Luža Square and turn right past the Bell Tower; the palace is fifty metres ahead on the left, with the cathedral immediately beyond it. A single Dubrovnik Museums ticket covers this building along with the maritime, ethnographic and archaeological collections, which makes it good value if the weather turns. The ground floor and atrium are level and enterable with a wheelchair; the upper floors are reached only by the historic staircase. Mid-afternoon is the busiest hour, as the walls circuit empties into this quarter; late afternoon, after four, the courtyard is quiet and the low sun crosses the arcade at an angle that flatters the capitals.