150 US - Mammoth Cave National Park (1981)

Brief Description

"Mammoth Cave National Park, located in the state of Kentucky, has the world's largest network of natural caves and underground passageways, which are characteristic examples of limestone formations. The park and its underground network of more than 560 surveyed km of passageways are home to a varied flora and fauna, including a number of endangered species."

猛玛洞穴国家公园
"猛玛洞穴国家公园位于肯塔基州，是世界上最大的自然洞穴群和地下长廊，也是石灰岩地貌构成的典型代表。该国家公园及其地下 超过560公里的长廊为多种植物和动物提供了栖息地，其中包括许多濒危物种。"

Source UNESCO WH website http://whc.unesco.org/en/list/150

Courtesy of nhigh from postcrossing forum

Place of Origin postmark