Apart from the National Geo Park which I recommended previously, there is couple of other locations of interests. The ancient culture Tin Hau Temple and the contemporary culture Hong Kong University of Science and Technology (HKUST).
An ancient clock at the campus
View detailed transportation guide and map of the HKUST
The Tin Hau Temple at Sai Kung is the largest among all Tin Hau Temples in Hong Kong and has the longest history. Locals call it 'The Grand Temple 大廟'. All Tin Hau Temples are facing the sea as Tin Hau is the God of Sea, safe guarding the fishermen’s life in ancient times. Here you’ll witness how wonderful the location of the Temple is. Apart from superb seaview, you can sense tranquility and peacefulness here.
Tin Hau Temple at Sai Kung