Painted from a photo I took in Japan of Odawara Castle, located in Kanagawa, which was owned by the Hojo clan. The inks were done by hand and then scanned into Photoshop for the painting. Naturally I had to put their "triforce" crest in there which the Hojo clan used!
 
The calligraphy reads:
小田原城: Odawara Castle
 
This only comes as a 12"x18" matte print. There is no metal version of this illustration.