Shiba park is one of the oldest parks in Japan, opened to the public in 1873 together with another 4 parks, Ueno, Asakusa, Fukagawa and Asukayama. The parkland used to be very wide including grounds of Zoujo-ji Temple, but those grounds were separated and occupied by the Temple after the war, which made the shape of the remaining park to a ring-shape. In the park, they have an artificial gorge called "Momijidani", where you can enjoy nice view of the water fall of 10m high together with various types of rocks and tall trees. You will feel as if you are staying somewhere in deep mountain areas.
Momijigari is the Japanese tradition of visiting areas where leaves have turned red in the autumn. The word comes from the two Japanese words momiji meaning "red leaves" or "maple tree" and kari, "hunting". It is also called kouyou. "Kouyou" is another pronunciation of the characters for "momiji". In Hokkaido another word for it is kanpuukai (観楓会).
Many Japanese people take part in this. The tradition is said to have originated in the Heian era.