I stumbled across this spot. The castle itself is not too far from Odawara station so it can make a nice quick addition to a trip in the area as you can spend any amount of time at the spot and get something from it. There are multiple entrances to the castle itself with a few other attractions such as the aforementioned zoo. There is also a ninja museum. In the summer, there are stalls that offer ice cream and kakigori: a shaved ice dessert. The castle is flanked by a moat and an incredible shrine featuring koi. Overall, would highly recommend.