Pop = 3 million.
1. Balboa Park. It's gorgeous and well worth a visit. Lots of grass and trees, plus regular maps to show you where you are, which was very handy for a first timer. I walked over a lovely bridge across the freeway and into a sprawling complex of Spanish style buildings [not surprising, given how close San Diego is to Mexico]. These include a hot house which looks like a huge bird cage. I proceeded to the zoo and spent seven hours there [with a lunch break!] seeing all the animals. There's a free tram which runs around the park and I hopped on that to shorten my return journey. The driver is planning to come to Nottingham and was asking for information!
2. Flying home
The plane took off and headed out over the Pacific before performing a U turn to get to Detroit. We flew over California and the terrain soon became brown, desert-like and craggy. But the more fertile plain is laid out in huge regular squares, as far as the eye can see. In this part, the squares were mostly filled with circular patches of green - crops? - which made me think of a giant sheet of green stickers! Then the terrain reverted to desert and became even rockier, looking just like aerial shots from a cowboy movie! We went over the Grand Canyon; I recognised it by the look of it and the green river at the bottom, plus the stewardess confirmed my guess. Then, more regular green squares; mostly farms and small collections of houses. The only thing which altered the pattern were hills, the odd freeway and pesky meandering rivers! We went over Lake Michigan and finally into Detroit itself, which was a lot greener than I'd expected. Tree lined streets, small lakes and lots of grass. And still the basic square pattern. I mean, I knew; but I'd never flown low enough over the US to see this phenomenon so close.
Pix [http://www.flickr.com/photos/30367056@N02/sets/72157624644019792/ ]