Okay, I admit it. I'm a sucker for good engineering. One of my favourite Primo Levi books is The Wrench, a novel about a rigger who specialises in cranes and bridges. Gotta love those bridges.
This series begins (and possibly ends) with the bridges of Zimbabwe. Here are some beautiful structures that you may not be aware of:
Birchenough Bridge
Designed by Ralph Freeman, the designer of Sydney Harbour Bridge
Beit Bridge
Okay, not so pretty (but important) and not to be confused with:
Otto Beit Bridge
Then there's Victoria Falls Bridge, also designed by Freeman.
(In fact, I'm not sure, but I think all these bridges were designed by Freeman.)
UPDATE: Brian Corbett, who initiated the wikipedia entry on Birchenough Bridge, emails to point out that the rather wonderful photograph of the bridge was taken by this guy.