Through the Sister Parks program, national parks in the United States share a mission of environmental stewardship with similar parks around the world.
Participant countries enter a five-year agreement, overseen by the U.S. Department of State’s Office of International Affairs, with the United States allowing park rangers from both nations to share conservation tips and best practices for caring for important parks, sites and monuments.
Over three dozen Sister Park partnerships link parks in the United States with ones in 32 other countries.
Here are five of these Sister Park partnerships, united by a common goal of protecting the Earth and important cultural sites.

On March 21, the governments of the United States and Ireland signed a joint agreement establishing Glacier National Park in Montana and Killarney National Park in County Kerry as Sister Parks. Irish legend says the builder of Ross Castle, O’Donoghue Mór, lies beneath the lake and wakes up every seven years to ride a white horse around it. While no such legends exist for Glacier National Park, it does encompass over 404,000 hectares and 130 glacial lakes.

The USS Arizona Memorial, part of the World War II Valor in the Pacific National Monument, in Oahu, Hawaii, and Australia’s National Maritime Museum in Sydney both honor their countries’ naval endeavors. The U.S. government also sponsors a gallery inside the Australian museum.

The Everglades National Park in Florida and Pantanal National Park in Brazil are both wetland conservation areas. The latter lies within Brazil’s Pantanal region, one of the world’s largest freshwater wetland ecosystems, while Everglades National Park protects 20% of Florida’s original tropical wetlands and is the largest tropical landscape in the United States.

Mammoth Cave National Park in Kentucky partners with the South China Karst World Heritage Site in Guangxi province. The South China Karst World Heritage site sprawls over 97,125 hectares and contains significant karst landforms — underground drainage systems formed by the gradual dissolution of rocks. Mammoth Cave, similarly, is the longest cave system known and is home to a rich diversity of plant and animal life.

Lake Roosevelt National Recreation Area in Washington state is “sister” to Spioenkop Nature Reserve, a protected area in KwaZulu-Natal, South Africa. The Spioenkop reserve is 4,400 hectares of diverse ecohabitats while Lake Roosevelt is connected to the Grand Coulee Dam, a historic hydroelectric plant.