The Marquis de Vauban was a 17th century French military leader and the foremost military engineer of his time. His name lives on as defining a style of fortification which used intricate geometry, trenches, advanced redoubts, and interlocking fields of fire. In early 2012, a French history museum staged an exhibition that contained models and dioramas of many of the fortifications that Vauban supervised the construction of or the siege of. A key part of the exhibit was intricate three dimensional models that replicated the fortifications and terrain in exacting detail. The sheer size of some of them has to be seen to be believed.

http://lurkerablog.files.wordpress.c...2/img_1197.jpg
http://lurkerablog.files.wordpress.c...2/briancon.jpg
http://www.nicematin.com/media_nicem...oto-245294.jpg
Briançon au Grand Palais | Flickr - Photo Sharing!
Exposition des Plans Reliefs dans la nef du Grand Palais de Paris du 18/01 au 17/02 2012 - Le blog de diorama-militaire-ho.over-blog.com (incredible link, scroll down to see the 3d models, at the bottom are two videos (in French) describing the models)
Musée des Plans-Reliefs : Accueil