I have a 100 gallon Rubbermaid stock tank in my basement that houses my pond fish in the winter. The younger of my two cats is entranced by it. She has a perfectly good water fountain upstairs, but she likes to walk around the smooth, curved edge of the stock tank, find just the right spot, and then turn to face the tank and take a drink. She looks like a trapeze artist, with all four feet in a line. I have to get a picture...it is pretty impressive.
I know she has fallen in at least twice...the filter box has ended up on its side twice. She must have used it to escape...oh, how I wish a had a picture of that!