This cover from USA depicts 3 stamps, including the stamp on the right corner celebrating the
Carlsbad Caverns National Park.
Carlsbad Caverns was added to the UNESCO World Heritage List in 1995, stating that the site is of Outstanding Universal Value based on its exceptional and geological features, unique reef and rock formations, and containment of major cave formations. The reef formation is rich in sea fossils over millions of years, created a massive limestone formation. Several deep canyons in the Capitan Reef formation reveal cross-sections of other formations that have been exposed within the Carlsbad Cave system, including one of the most notable caves in the park, Lechuguilla Cave, which had only been discovered as of 1986 according to the NPS and is currently the deepest and the third longest limestone cave in the site and is home to the largest collection of natural hydromagnesite, helictite, and calcite formations (UNESCO). Carlsbad Caverns continues to form new structures and serves as a highly valued space for scientific research on the geological and biological systems of the park.
