Fung Sin Koo Temple (馮仙姑廟) is a shrine/temple located at 22 Tin Hau Temple road, IL 1697 R.P.
Many websites only stated this temple alongside the Tin Hau Temple, with no description and history of it.
From a random Chinese forum, they stated people celebrate Tin Hau (Empress of Heaven) Festival in the Fung Sin Koo Temple and Tin Hau Temple in the 1880s.
1913 to 1915 maps first show the temple as "Fung Sin Ku Temple", in the middle of the mountain with no trails or paths connecting.
In 1919, the Chin Woo Athletic Association established their first school in Hong Kong at a lot near the Fung Sin Koo Temple, Tai Hang.
The 1924 Plan of City of Victoria shows it as "Fung Sin Ko Temple", and resembles a "L" shape structure.
The temple appeared on the 1938 HK street index page 307, this is where I found the temple's lot number and address.
Thevoice magazine stated that the Fung Sin Koo Temple exists around the WW2 period, built before, and closed afterwards.
It appeared on the 1961 survey map first, up until the 1978 survey map, which was the last map to show the temple. In the 1982 aerial map, a silhouette/unclear shape of the temple was shown, but disappeared in later images. The 1983 map shows ruins in that spot.
The Chinese Temple Committee stated that the Fung Sin Koo Temple collapsed, and the Fung Sin Koo statue was reallocated to the Pak Tai Temple in Wan Chai.
In 1987 March 25th, the Dragon View Garden was opened, replacing the temple and nearby structures.
Sources:
Douban.com (Chinese forum)
Thevoice.org.hk (pdf of 1 page)
Terraces in Tin Hau (Facebook link)
HK maps viewer
1938 HK Street Index, page 307
Chinese Temple Committee, Pak Tai Temple