I have three ponds. That pic is the smallest and closest to the house. I have 4 shubunkin and 2 butterfly koi who live there with the frogs. Those are small bird houses. I used to collect them but stopped. The weather got to most of them. I miss them. They do add a bit of whimsy in the yard. I am thinking about starting up again. A pair of house wrens actually built a nest in one, til a critter chased them out. Sad. A better view of the little pond.
Here's one of my other two ponds, made to look like one separated by a bridge. One for koi and the other for goldfish.