What is Japan's Top 100 Castles??

This blog records trip to Japan's Top 100 Castles.
Then, what is Japan's Top 100 Castles??
The HP of the Japan Castle Association(日本城郭協会) says follows:

The selection of "Top 100 castles in Japan" was planned with the support of the Ministry of Education, Culture, Sports, Science and Technology and the Agency for Cultural Affairs as a project to commemorate the 40th anniversary of the Japan Castle Association becoming a foundation, and the following 100 castles were planned in February 2006.
The castle and castle ruins, which are the representative cultural heritage of Japan and the historical symbol of the region, were set with the intention of making many people aware of them, raising their interest, and eventually leading to the promotion of regional culture. 「日本１００名城」の選定は日本城郭協会が財団法人となって４０周年を記念する事業として、文部科学省・文化庁の後援を得て企画され、以下の１００城が平成１８年２月に発表されました。
日本を代表する文化遺産であり地域の歴史的シンボルでもある城郭、城跡を、多くの人に知ってもらい、関心を高め、ひいては地域文化の振興につながることを念じて設定されました。 Public Interest Incorporated Foundation Japan Castle Association HP (公益財団法人　日本城郭協会　HP)

Anyway, let's start our tirp to castles that represents Japan!