Quite a few of the film's fight scenes were filmed on top of the King's Park covered reservoir garden. I've mentioned this place previously on my other blog because it's the same area that the real Bruce Lee was photographed training in kung fu with his dad and "uncles". You can see some modern images, courtesy of yours truly, at number 1 on this link.
In this film it's the area where Bruce Li/Ho Chung Tao's character trains and seems to always get ambushed, you'd think he would learn after the first couple of times. Anyway, the first two images are of the steps and path way that lead up from the back of Cliff Road and Wing Sing Lane.
The steps and path are still there but the steps now have a green canopy covering them. You can access them , as mentioned, from Cliff Road just off Nathan Road. Later on, there is also a snippet of a training scene that was filmed actually in the rest garden atop the covered reservoir.
The small white building at the back of the first two images above is the pump house that can still be seen today. There is a close up picture of it on the link I provided earlier, but you can see it here as well.