This is the Lost City of Atlantis. I designed it because I could not find a sizable fish tank display for my tank. My other reasoning is that a sunken ship is way to clichè. My fish smiled after I sank the city in the tank. They have marked their territories in different spots. There are lots of places to hide and this is friendly for all types of fish.
I feel this would be a great Lego set, because it is fun to build and there is nothing like it. I have yet to see any production Legos that are actually under water. This is a territory that I do not believe Lego has explored. With the simple adding or subtraction of pieces this set can be customized to your tank size. Furthermore people like this build more than the gigantic city I have in my basement.