Chia-Lo Jinja was biult in 1918, during the time Taiwan under Japanese rule, in the old Taiping Mountain (The Taiping Mountain in Yilan today is the new Taiping Mountain). The old Taiping moutain was developed for its forest resources from 1917 to 1937. It was recorded that there was once an elementary school near the Jinja.
(images from http://www.yilanwalker.com/AVSEQ81.htm)
What can be seen today are the stairs connecting the three layer structures of the Jinja, the base for the column of Toriis, some glass and ceramic bottles, and a huge sacred tree (which can also be seen in the old pictures above! ^_^)
BTW, there are some really useful resources for mountain hiking in Taiwan!
Topography map pdf file generator: http://map.happyman.idv.tw/twmap/login.php
Topography map for Garmin devices: https://sites.google.com/site/asterosmtaiwantopo/garmin