It's no secret that for me, there's great value in even a brief stop in far flung destinations. Whether on a long layover, or a short turn-around, a day, or even less is time that can be well spent sampling a new city. Of course a short trip can't be expected to result in a thorough exploration, but it's plenty of time to 'see one thing.' Many people ask me why I would fly across an ocean to be there for only one or two days. The answer, that for the most part satisfies is, "isn't one day better than no days?"
A prime example of a place that can be enjoyed in short order, is Hong Kong. When I find myself there, I have a tradition of going early the morning after I arrive to Victoria Peak. If you happen to get there soon enough, before the city wakes, you'll find yourself in the midst of decadent jungle trees and vines, with only the birds and the occasional local out for an early run for company. No lines, no crowds. There's something surreal about being in the heart one of the most densely populated places on earth, and feeling like you're the only one there.
Victoria Peak is easily accessible via the (very steep) cable car that climbs up from a station adjacent to Hong Kong park. You can get there fairly easily from either the Hong Kong or Kowloon side hotels on the light rail or on foot, depending on how far you're going.
Once you arrive, an easy walk around the "Morning Trail" takes you on a loop encircling the peak, allowing views of the city below from all angles. There are longer trails and hikes in the park as well, and a visitors' center with food, souvenirs, and an observation deck. Arriving early is the perfect use for your jetlag.