Dingneijian is located in Nuannuan District, Keelung City. The mountaintop offers excellent views, with distant vistas of the sea off Keelung Harbor and Keelung Island.
Izumi-no-Tseng also has the ruins of an ancient fort from the Qing Dynasty, making the mountain not only a natural landscape but also a historical site.
In the past, the path to Dingneijian was in poor condition, requiring people to climb steep mountain paths by holding onto ropes. As a result, apart from mountain climbers, few tourists from outside the area visited.
The Dingnei Community Development Association, through mutual assistance and self-reliance, brought together community residents to lay stone slabs and build a hiking trail leading from Guanyin Temple to Dingnei Peak. After its completion, Dingnei Peak transformed from a less-visited mountain path into a scenic trail suitable for the general public, with a 20-minute walk to the summit where visitors can enjoy stunning sea and sky views or visit historical sites.