Green Infrastructure (GI) can be used as a framework for planning human settlements and guiding development away from natural areas that possess high ecological value and provide important Ecosystem Services for society's development. In this paper, we present a GI Plan for Yesan County (Yesan GI Plan), a small shrinking city in the Republic of Korea. Yesan possesses very rich, but still fairly unexplored natural and cultural resources. Therefore, Yesan's GI Plan was developed through a multifunctional approach based on the different ecological and socio-cultural characteristics of the region, allowing to connect the core elements that conform the vernacular landscape and get the most out of the Ecosystem Services provided by resources in the area. The plan was defined mainly in two stages: first, applying weights to the different ecological and socio/cultural characteristics; secondly, arranging them through a set of GIS spatial analysis tools using a patch-corridor-matrix model approach. The final outcome is a lean network of ecological value hubs, connected to a set of socio-cultural value assets through a network of water bodies, intrinsic forestry characteristics and wildlife mobility in the area. This was followed in order to connect, facilitate and improve mobility and energy flow in Yesan.