Info from Hong Kong's Great Outdoors
Relatively wild valley with two beautiful waterfalls – Bride’s Pool and Mirror Pool falls. The Bride’s Pool fall is visible from beside the road, but the more spectacular Mirror Pool fall is hidden unless you walk down to cross a stream, then head up into a ravine. Short streamside walk to the top of Mirror Pool from a nearby village, Wu Kau Tang.
Bus 275R from KCR East Rail Tai Po Market Station, on Sundays and public holidays; or walk, cycle or taxi from Tai Mei Tuk.
Also Minibus 20C (special), from Tai Po (Nam Shing Street) [via Tai Po Market East Rail station?] to Wu Kau Tang [note - times may change]:
Tai Po Market: 0545,0645,0745,0945,1145,1445,1545,1745,1845,1945
Wu Kau Tang: 0615,0715,0815,1015,1215,1515,1615,1815,1915
A brief summary of places you can rent bicycles in Hong Kong.