Here's somewhat of what I've been doing this summer.
It's about a 200 gallon pond, with 1800 gph river/waterfall. There's about 2 tons of rock in there. ^_^ It's a wonderful place to sit and read or just sit and think.
It's my geek antidote!
There's also three fish in there. They hide in the rocks, and (I assume) come out at night to eat.