120°35'N, 23°37'L is the precise location of Gukeng. Lye in the east is Chu Keng Tzai of Tsao Ling Village, which connects Chu Shan Township of Nantou County and Wu Feng Township of Chiayi. The west side is Ma Yuan Village, Hsin-Chuang Tzai, neighbouring Dou Liou City and Dou Nan. Toward the south, is Lu Tzai of Tsao Ling Village, neighboring Mei Shan and Chung Pu Township of Chiayi. In the north is Chi Pan Village, which is the district with the largest land mass under governance and the most mountain area.
Gukeng is 60to 1750 meters above sea level. The area has varied altitudes sloping toward the west. Most lands in Gukeng are of mountain area with little flatland. The farming area consists barely over 5000 hectares, and rest of the areas are mostly forests. Therefore the area is rich is forest produce, such as bamboo shoots, pineapples, kumquats, and passion fruit. Geologically, the soil of Gukeng is of Nan Chang bed and Guei Chu Lin bed from 3rd century, main rocks include sandstones and gray shale. Around the river areas is diluvium of the 4th century. The soil is gray yellowish with gravels. The arenaceous soil is almost sandy with little adhesive property. The soil is quite neutral, mainly due to the geographical features and slopes, which results layers of different soil properties. However, the gentler part of the slope has thicker soil layers, while steeper slopes are covered with only thin soil layer due to the washout effects.