Yesterday i've received a lot of cards, one of them was this japanese card with the Odawara Castle. Even though this is a japanese card, sent from Japan, the ID is polish. Apparently the sender travels a lot.
Odawara Castle is probably the best example of a castle to visit in the immediate Tokyo area.
"The Odawara castle is actually a restoration of the original castle. The original castle was constructed in 1590 by the lord Ujinao Hojo. It was later beseiged and taken over by the Okubo Clan. Fires, wars and earthquake all took their toll on the original building. The new construction was completed in 1960. The viewing area at the top of the castles offers some nice views of Odawara city and nearby Sagami bay. The inside of the castle houses an interesting collection of samurai armour and swords. On the grounds of the castle there is a somewhat out of place small zoo and an elephant." - in: http://www.tokyoessentials.com/odawara.html