I will just say this up front, Kamakura has so much to offer that it would be foolish to miss this place if you visit the Tokyo region. It has many great temples and shrines as well as places to eat and shop. I only got to spend a few hours at this place, so I mostly focused on historic temples and shrines. This post will only focus on the three major ones from my trip: the Kōtoku-in Temple, the Hase-dera Temple and the Zeniarai Benzaiten Ugafuku Jinja Shrine.
The outdoor bronze statue of the Great Buddha of Kamakura (Amitābha Buddha) is located at the Kōtoku-in Temple and it is a great site to behold. This place offers many photo portrait opportunities, such as photo merging and panos. However you would need about 50 Sb-900s (aka Joe McNally) to properly light the buddha and a few more for your subject(s). I am currently still working on a few experimental photos from the location shot with a 50mm 1.8. The only downside to this location, both photography and visitor wise, is that this place is packed with visitors.
The Hase-dera Temple features many statues of the Jizo Bodhisattva (Buddhism), who is the protector of deceased children. Jizo Bodhisattva guides deceased children to salvation by hiding them in his robe from Hell. Along with the Jizo statues, there are also two Golden buddhas housed at the top of the hill. Photography is strictly forbidden and you will be reminded constantly about the policy. It does however give you a nice view of the nearby beach. At the bottom of the hill there is a small cave (Benten-kutsu) that houses several minor gods. The cave is very exciting, but has little light (was forced to shoot ISO 3200) and very tiny. There are some areas where the clearance is only .9 meters (3 feet).
The last place I wish to mention is the Zeniarai Benzaiten Ugafuku Jinja Shrine. It is located near the top of a hill and it is a challenging walk, especially if you are out of shape. This place is interesting because it features two unique things. First, people come here to multiple money by blessing it with the water. Second, it features the triforce symbol that many people associate with the video game series Zelda. But the symbols are actually the family crest of the Hōjō clan. Since this place is a bit hard to get to and is not as known as the other temples for mentioned, there is little foot traffic and it allows a bit more photographic-room. I think the best time to get shots would be early April (Sakura blossoms) at either sunrise or twilight. At these times, you would have a lot of back drops to chose from including a waterfall, several shrine structures and a shot overlooking the shrine and the nearby town.
Kamakura tourist website (English): http://www.kamakuratoday.com/e/
These are beautiful. I think it would a great time to come to Japan in the warmer months when every thing is in bloom.
Are there very many species of tropical fish, (if any) in these water fall ponds?
You did not mention fish. Were there any in the ponds at the water falls?