Larry Dighera writes:

But I think KSAN is even more difficult to visualize:
http://skyvector.com/#32-25-3-3647-2226 . It has VFR tunnels through
various Class B sectors.

The VFR corridor at least follows the shoreline; conceivably one could
navigate through it just by looking at the ground.

There aren't any VFR corridors at all in Phoenix that I've noticed.