Ratchaprasong Sky Walk

Think of it as infrastructure first and a sight second. This elevated walkway runs above the Ratchaprasong intersection, linking the big shopping centers, hotels and BTS stations so you never have to gamble with the traffic below. If you're doing a day around central Bangkok, you'll end up on it whether you planned to or not, and you'll be glad of it.

The views are the bonus. From up there you get the shrines, the crossing and the wall of malls laid out in a way you simply don't see from the sidewalk. It's a good spot for a photo of the city doing what it does, especially as the lights come on. I wouldn't make a special trip for it, but I would slow down halfway across instead of powering through like the commuters do.

Crowds are the main variable. Early morning is quiet and easy. Midday through evening it fills with shoppers and office workers, and moving with a suitcase or a pushchair gets awkward.