Question: I've heard that Hong Kong is really, really crowded and polluted. Will I be able to stand it?
Mr T replies: You may find the pollution distressing at times, but there are also many parts of HK that are amazingly unaffected.
Air pollution is a problem in Hong Kong - there's no denying this. But in many outlying areas such as Sai Kung and the south side of Hong Kong Island, it isn't as bad as right down amongst the skyscrapers downtown. A lot of the pollution in HK drifts down from southern China when the winds are from the north, and covers the whole city. When the winds are southwesterly, which is the prevailing directing in the summer, it's often far better.
Hong Kong has quite a few beaches, and most are all right for swimming, if not pristine. I've certainly swum in Deep Water Bay and Repulse Bay (on Hong Kong Island) and Clearwater Bay (in the eastern New Territories) numerous times with no ill effects. The water is at its best in the autumn, when the weather here is dry. In the summer, the water tends to be a bit muddy, because there's so much runoff from the heavy rain we get. A more remote beach, Tai Long Wan, is particularly good -- by far the best beach in HK, by my reckoning, and I know Mr B concurs. See his series of hiking photos of a trip to there here. There are also some decent beaches on Lantau Island, and lots of little 'unofficial' beaches you can get to by hiking only.
Hong Kong is also very mountainous. The built-up areas account for only about 10% of the land area, so there are actually places you can get totally lost in the wild. Both Mr B and Mr T like to hike, and we've got lots of information on this on our hiking page.
All in all, the situation is lot better than you might expect from the world's most densely populated city!