Odawara is a rather sleepy town in Kanagawa except for its castle, which is beautiful in the spring around cherry blossom season, and full of life year round. The castle itself is a replica, and has been turned into a musuem with lots of samurai swords, guns and other paraphernalia of the age. There is also a costume shop that rents out kimono and samurai uniforms--A LOT OF FUN!
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Find out more about Odawara Castle.