A military deterrent, constructed from wood, paper and silk? A royal and imperial toy collection? A time machine? A 17th century Google Earth?
Forgotten gems from the world's largest and finest collection of old models of urban and rural landscapes go on exhibition in Paris from this week. For the next month visitors to the Grand Palais can marvel at Lilliputian versions of Strasbourg or Besançon or Grenoble, as they looked from aeroplanes long before aeroplanes existed. They can also rediscover the beauty and grandeur of two doomed French seaports, Brest and Cherbourg, which were pulverised by allied bombardments in 1944.
The startlingly beautiful models are among 200 "relief maps" of fortified towns constructed for French kings and emperors from the late 17th century to the mid-19th century. For decades, most of the models have gathered dust in the store-rooms of the Invalides. In the last few days, sixteen of the best-preserved have been lovingly reassembled in the nave of the Grand Palais exhibition hall off the Champs Elysees.
The models, built to a scale of 1/600, include not only the towns and their fortifications but swathes of the surrounding countryside or mountains. One of the many joys of the exhibition is to travel back in time to visit the surprisingly familiar, farming landscapes of the late 17th and 18th centuries.
Among other reasons, the models were constructed in order to work out the possible lines of fire for besieging artillery. As guns grew more powerful, the modelled area had to expand.
The later models, those of Brest and Cherbourg, are almost as large as tennis courts. They were ordered by the Emperor Napoleon in the early 19th century to help plan the defence of France's Atlantic naval bases from possible attack by the Royal Navy.
They show, in poignant detail, the lost beauty of two towns flattened by British bombing and American sieges during the Second World War. Brest and Cherbourg were hurriedly rebuilt in box-like concrete in the late 1940s.
Isabelle Warmoes, an expert on French military fortifications and one of three curators of the exhibition, said: "Other countries built similar models from the 17th century but few of them have survived. We still have about a hundred in the French national collection, which is almost certainly the finest in the world."
The earliest models, built in wood, paper silk and metal, go back to the late 17th century when France was fighting constant wars to defend, and expand, its northern and eastern borders. King Louis XIV ordered the models so that he could inspect and plan the defences of frontier towns without moving from Paris.
"Successive kings were very proud of the models," Ms Warmoes said. "They showed them off to selected foreign visitors, partly to show just how strong the defences of the key frontier towns were. They were a form of deterrent against attack."
Parts of the accompanying exhibition in the Grand Palais have been sponsored by Google, which sees the models as a pre-computer-age prototype for its own Google Earth satellite mapping website. When the exhibition ends on 17 February, most of the models will be stored away once again.
Strasbourg in the early 19th century is still largely recognisable today. The Prussians "stole" an earlier model after France's defeat in 1815 (and then annexed the real city in 1870). This 72-square metre model was built in 1830-36 and updated to include early railway lines in 1852 and 1863.
This five-metre square model, built between 1802-5, shows the city (now capital of the independent Duchy) and its fortifications after it was captured in a seven month siege by the French in 1795.
Embrun, in the French 'Hautes-Alpes', near the Italian border, was captured by the Duke of Savoy in 1692. This 11-square metre model was commissioned in 1701 by King Louis XIV to show the fortifications built by the great French military engineer, the Marquis de Vauban, after the town was retaken.
The most moving of all the models, this extraordinary 130- square metre panorama shows Brest at the height of the Napoleonic wars in 1807. During the Second World War, the city was pulverised by RAF attacks on German naval bases and then flattened in 1944 during a US siege.