Doesn't that look like a perfect little house for a river otter? From the front door an otter could slide into the water to do some swimming and fishing. He could play all day in the water and then come back to rest in the warm dry house for the night. He would have lots of time to play since he wouldn't have much grass to cut in the summer, leaves to rake in the autumn or driveway to shovel in winter.
This house for a river otter is actually a boathouse on a river, but I bet otters use it too. There might be a few in there right now, sitting around a table in their warm little otter slippers, eating goldfish crackers and playing cards. Go Fish I bet.