I'm sure anyone who knows Osprey publications is familier with the Fortress series but if you're not, and you like field works and forts, you should look this series up. They are excellent with the usual great illustrations and photos. Many wonderful construction details are illustrated as well as how the works were used and functioned. I have #24, "Fortifications of the Western Front, 1914-18", and #103, "The Fortifications of Verdun, 1874-1917", as well as the one on the defenses of Corregidor and Manila Bay, (#4). They are incredibly interesting and well worth the bucks. There are all sorts of other titles including ones on French and British forts in America (FIW). -- Al