日本100名城 (Nihon hyaku meijo) means "Japan's 100 fine castles." They were chosen by the Japan Castle Foundation, a public-interest body that has promoted castle research and preservation since the 1950s, as a project marking its 40th anniversary as a foundation, with backing from the education ministry and the Agency for Cultural Affairs. The public nominated sites between August and October 2005, a selection committee chaired by Shintani Yoji, professor emeritus at the University of Tokyo, with six specialists in architecture, civil engineering, archaeology and history, met on December 1, 2005, and the 100 were announced on February 13, 2006. Certificates went to the castles on April 6, 2006, Castle Day, because 4 and 6 can be read shi-ro.
The committee worked to three criteria: outstanding cultural properties and historic sites, famous stages of history, and castles representative of their era and region. It also set a quota of at least one and at most five per prefecture. That quota is why the list looks the way it does. It spreads a national list evenly over a country whose castles are not evenly spread, so Hyogo gets five and Tochigi gets one, and the entries stretch the word "castle" a long way: no.1 is a group of 24 Ainu clifftop enclosures on the Nemuro Peninsula, no.7 is an 8th-century frontier headquarters, no.88 is a Yayoi-period moated village, and no.2 is a star-shaped fort finished in 1866. Several entries, including Ashikaga and the Takeda residence in Kofu, are fortified houses that never had a tower at all.
What turned the list into a national pastime was the stamp rally, launched in June 2007. Each of the 100 has a numbered rubber stamp, usually at the ticket office, museum reception or visitor centre rather than at the ruin itself, and the stamps only count if you press them into one of the foundation's official stamp books. The books are not sold at the castles: they come bound into the foundation's guidebooks, so you buy one before you start. When your book is full you post it to the foundation, which stamps it with a 登城完了印, a completion seal, writes in your rank in the order the books arrive, and posts it back. There is no fee for the certification, and your name goes on the foundation's site only if you also donate. Stamp locations move, some castles cannot stamp at weekends, and closures happen, so check before a long detour.
This is a different list from the 12 original castles, and the two get mixed up constantly. The 12 originals are not a chosen list at all: they are simply the castles whose keep, the tower at the centre, was built before 1868 and still stands. All 12 are here (Hirosaki, Matsumoto, Maruoka, Inuyama, Hikone, Himeji, Matsue, Bitchu-Matsuyama, Marugame, Matsuyama, Uwajima and Kochi), which means 88 of these 100 have no original keep. Some have a concrete keep put up in the 1950s and 1960s, some have a timber one built from Edo drawings and Meiji photographs, some have a tower that never existed in that form, and many have nothing above ground but walls, moats and grass. We say which in every entry, because that is the single thing people most often get wrong when planning.
In 2017 the foundation added a second hundred. The 続日本100名城, the Continued 100 Fine Castles, were announced on Castle Day, April 6, 2017, for its 50th anniversary, drawn from about 500 nominated sites and numbered 101 to 200. They have their own stamps, and the foundation certifies both rallies together in a single ranking, so "completing the 100" in the official sense now means 200 stamps. This page covers the original 100 only. Numbers 101 to 200 will get their own page.