I don't know why I know this but:

Alameda didn't used to be an island. It was a little peninsula until the construction of a canal severed it from the mainland in 1902.

The navy base is built on a chunk of the island that is actually LANDFILL. That's right. Quite a few Alamedans live not on land that is of any natural earthly origin, but on a large pile of compressed garbage and debris.

One more thing:
If you ever find yourself stranded in Alameda after attending a baby shower or some other function, Do Not Panic. Simply make your way north until you are in view of the tunnel that connects Alameda with the outside world. There is a road that leads into this tunnel. I believe it is called Webster Street, but I may possibly be wrong. Find this road. If you have no car, look for a bus stop and catch the 51 NORTH. It will bring you safely back through Oakland to Berkeley. If you are too lost to make it to any bus stops that say "51", I have no advice for you. I am sure there are other buses, but I do not know of them. There is another tunnel to Oakland someplace down there in the bowels of Alameda but I have never had the pleasure, and so cannot direct you to it. I offer you only the fruits of my own escape experience.

(Alameda is really not in the middle of nowhere. It just feels that way.)
It's true about the friendly people & pretty houses in some areas.
But I do not recommend pedestrial visits. :/