At this point in time, I'm aware of a few kayo that are meant to be odes to ancient Japanese castles, namely Michiya Mihashi's (三橋美智也) "Kojou" (古城) and Kiyoshi Hikawa's (氷川きよし) "Haku-un no Shiro" (白雲の城). I'm a fan of Michi's biggest hit and I'm in the midst of getting used to Hikawa's iconic single, but I hadn't yet got formally introduced to their spiritual predecessor "Kojo no Tsuki" until now.
"Kojo no Tsuki", which translates to "Moon Over the Ruined Castle", has a forlorn and haunting atmosphere, created by long drawn out strings and, in some versions I've heard, the tinkling notes of the koto (adds a more Japanese flavour). This eerie composition, written by the short-lived Rentaro Taki (滝廉太郎) in 1901, highlights the fact that these fortresses, once grand in their time, are now nothing but moss-covered ruins and remnants of the past. This brings to my mind the phrase "If the walls could talk, what would they be saying?". Perhaps the cobblestone walls must be lamenting over their fate of being forgotten or having been turned into a tourist attraction after being the epitome of power in their prime.
I digress. Moving on, the inspiration for the two aforementioned hits by the huge enka stars actually started out as a tune for music lessons in school. After Taki passed on, one thing led to another and some changes to his score were made and the lyrics were added by poet Bansui Doi (土井晩翠). Eventually, it did become popularized nationally as well as internationally in the 1920's, although I'm not very sure who was the first to record it. The English Wiki stated that operatic singer Yoshie Fujiwara (藤原義江) recorded it in 1925, but the J-Wiki has no mention of it. That aside, it was covered a number of times by a myriad of artistes, like the venerable Yoshiko Yamaguchi (山口淑子), Ichiro Fujiyama (藤山一郎), and of course, Michi and Hikawa. I'm not able to find Michi's take, but I've put up the others. I don't have a favourite, but I feel that Yamaguchi's soprano gives "Kojo no Tsuki" an extra layer of loneliness and eeriness.
A little tidbit of information here: The castles the words and the music were based on were different. Taki had Oita prefecture's Oka Castle in mind, while Doi pictured the Aoba Castle in Miyagi and Aizuwakamatsu Castle in Fukushima.
Personally, I've not visited many castles in Japan. The only one I've actually gone up to for a look was the Osaka castle about 4 years back. T'was a majestic sight against the night sky and it's nowhere near ruin, but to be frank, I was more interested in this enormous Siberian Husky or Alaskan Malamute (probably the latter) that was stationed inside a photo shop. I really wanted to give it some love but I was advised not to - the elderly shop owner seemed sour over people going into the shop for the dog and not for the photo services. Well, lady, what do you expect when you've got a dog big enough to be ridden into battle? I wonder if Fido is still there.