Anthony's Fish Grotto is a venerable institution in San Diego.

[photo from Anthony's website]

You can sit inside in the "grotto" at water level and feel like a fish.
(apparently there are bass in the lake too)

Anthony's own spring-fed lake sits just back of the restaurant.
That makes it a rarity among San Diego lakes. 
I suspect some of that spring is "fed" by leaks from the Grassmont Reservoir
just a mile away, uphill from the restaurant lake ...

You can also sit outside in the back next to the water, 
but you can't throw food to the dangerous ducks 
except from a special pavilion situated far away from diners.

This restaurant business is slightly older than I,
but this location is 10 years younger.

I can remember as a kid being very excited to eat here!