Which national park was established as the world's first national park in 1872? This American national park was signed into law by President Ulysses S. Grant on March 1, 1872. It spans 3,472 square miles (8,983 square km) across three states: Wyoming (96%), Montana (3%), and Idaho (1%). The park is famous for its geothermal features, including Old Faithful (a geyser that erupts every 44-125 minutes), over 10,000 hydrothermal features (geysers, hot springs, mudpots, fumaroles), and more than 500 active geysers (half of the world's total). The park sits atop a supervolcano that last erupted 640,000 years ago. It is also home to diverse wildlife: grizzly bears, wolves, bison (the largest public bison herd in the US), elk, moose, and pronghorn. The park receives about 4 million visitors annually. Its name comes from the Yellowstone River, which flows through it. The idea of a "national park" was invented here and has been copied by over 100 countries worldwide.

Which national park is the largest in the world, covering 972,000 square kilometers (375,000 square miles)? This national park is located in a country known for its vast wilderness. It is larger than the country of Egypt and almost as large as the entire country of France. The park was established in 1974 and is a UNESCO World Heritage site. It protects the world's largest fjord system (Scoresby Sund), the world's largest national park, and the second-largest ice sheet on Earth (after Antarctica). The park has no permanent human population – only about 400 people in summer and 40 in winter (researchers and military). It is home to polar bears, musk oxen, walruses, arctic foxes, arctic wolves, and narwhals. Most of the park is covered by ice, with only small areas of tundra vegetation. Tourism is extremely limited – only about 500 visitors per year, most arriving by expedition cruise ships. The park is located entirely within the Arctic Circle.

Which US national park is the most visited, with over 14 million visitors annually (more than Yellowstone and Yosemite combined)? This park is located on the border of Tennessee and North Carolina in the Appalachian Mountains. It is famous for its biodiversity (over 10,000 species), old-growth forests, 800 miles of hiking trails (including 70 miles of the Appalachian Trail), and its "smoky" blue haze created by volatile organic compounds released by the forest. The park is free to enter – no entrance fee (unlike most US national parks). It is an International Biosphere Reserve and a UNESCO World Heritage site. The park is home to black bears (about 1,500), elk (reintroduced in 2001), white-tailed deer, and over 200 species of birds. The most popular attractions include Cades Cove (a scenic valley with historic buildings), Clingmans Dome (the highest point at 6,643 feet), and the Roaring Fork Motor Nature Trail. Despite the crowds, 95% of visitors only see the park from their cars along a few main roads.

Which national park is home to the world's tallest trees – the coast redwoods (Sequoia sempervirens), which can grow over 115 meters (380 feet) tall? This California park was established in 1968 to protect 45% of the remaining old-growth coast redwood forests. The tallest living tree, Hyperion, is 115.92 meters (380.3 feet) tall – discovered in 2006. Its exact location is kept secret to protect it from tourists. Coast redwoods are the tallest trees on Earth, growing only in the coastal fog belt of Northern California. These trees can live over 2,000 years. The park is also home to 40% of California's endangered species. The park is jointly managed with California State Parks. The park includes prairies, oak woodlands, wild rivers, and 40 miles of wild coastline. The Roosevelt elk (the largest subspecies of elk in North America) is commonly seen in the park. The park is a UNESCO World Heritage site and an International Biosphere Reserve.

Which national park in Africa is the largest, covering 52,300 square kilometers (20,200 square miles)? This park in northern Botswana is part of the largest inland delta in the world – the Okavango Delta. The park has no fences, allowing wildlife to migrate freely across the landscape. It is famous for having the largest remaining population of elephants in Africa (over 130,000). The park is also home to lions, leopards, cheetahs, wild dogs, giraffes, zebras, hippos, crocodiles, and over 400 bird species. It is named after a former British colonial administrator. The park is difficult to access – most visitors arrive by small aircraft to remote airstrips. The park is a UNESCO World Heritage site. The best time to visit is during the dry season (May-October) when animals gather around permanent water sources. Unlike many African parks, this park does not have a large human population living within its boundaries, which helps wildlife conservation.

Which national park in Sweden, established in 1909, is the oldest national park in Europe? This park is located in the Swedish Lapland region, within the Arctic Circle. It is part of the Laponian Area, a UNESCO World Heritage site. The park is known for its dramatic landscapes: mountains, glaciers, waterfalls, and deep valleys. The park is home to the Sámi people (indigenous reindeer herders) who have lived there for thousands of years. The most famous trail is the Kungsleden (King's Trail), a 440-kilometer (270-mile) hiking route that passes through the park. The park's highest peak is Kebnekaise, Sweden's tallest mountain at 2,097 meters (6,880 feet). The park contains over 200 glaciers. Visitors can see wildlife including moose, arctic foxes, lynx, wolverines, and golden eagles. The park is very remote and has few roads – most visitors arrive by train or on foot. Winter temperatures can drop to -30°C (-22°F).

Which national park in Peru is considered the most biologically diverse in the world, holding world records for reptiles, amphibians, mammals, birds, and plants? This national park is located in the Peruvian Amazon basin. It holds world records: over 1,300 bird species (the most in the world), over 200 mammal species, over 300 reptile and amphibian species, and over 15,000 plant species (including over 1,300 tree species – more than all of Canada and the US combined). One hectare of the park contains more tree species than all of North America. The park is named after a former Peruvian president and was established in 1973. It is a UNESCO World Heritage site and one of the largest protected areas in the Amazon (18,000 square km). The park is home to indigenous peoples who have never had contact with the outside world. The park is threatened by illegal gold mining and logging. The park is extremely remote and has few visitors – most arrive by boat.

Which national park in Peru is home to the Colca Canyon, the world's deepest canyon at 4,160 meters (13,650 feet) – more than twice as deep as the Grand Canyon? This national park was established in 1973 to protect the Colca Canyon and the surrounding Andean ecosystems. The canyon is home to the Andean condor (Vultur gryphus), one of the world's largest flying birds with a wingspan up to 3.2 meters (10.5 feet). The best place to see condors is the "Cruz del Condor" viewpoint. The canyon was carved by the Colca River, a tributary of the Amazon River. The canyon is twice as deep as the Grand Canyon (which is about 1,800 meters deep). Pre-Inca terraces (agricultural terraces) line the canyon walls, some over 1,500 years old and still in use. Local villages maintain traditional Quechua culture. The park is also home to volcanoes, hot springs, and vicuñas (wild relatives of alpacas). The park receives about 150,000 visitors annually.

Which country established the world's first marine national park in 1935? This national park is located off the coast of a European country. It protects a series of islands, reefs, and marine habitats. The park was created to protect seabird colonies and marine life from overfishing and hunting. It is a UNESCO World Heritage site. The park is home to seals, dolphins, whales, and thousands of seabirds (including puffins). The park's islands are known for their limestone cliffs and sea stacks. The park has no permanent human population, but it does have a research station. The park is only accessible by boat and has no visitor facilities – all visits require permission. The park is named after the largest island in the group. The country is known for its progressive environmental policies and has protected over 25% of its land and 30% of its marine territory. The park is also a designated Biosphere Reserve.

Which national park in Nepal contains the world's highest peak, Mount Everest (8,848 meters / 29,029 feet)? This national park was established in 1976 and is a UNESCO World Heritage site. It covers 1,148 square kilometers (443 square miles) in the Himalayas. The park includes not only Mount Everest but also Lhotse (the fourth highest peak at 8,516 m) and Nuptse (7,861 m). The park is home to the Sherpa people, famous for their mountaineering skills. The park contains unique high-altitude wildlife: snow leopards, red pandas, Himalayan black bears, musk deer, Himalayan thars, and over 200 bird species. The park includes the famous trekking route to Everest Base Camp (5,364 m / 17,598 ft). The park has no roads – all access is by foot or helicopter. The lower elevations (2,500-4,000 m) have forests of rhododendron, birch, and pine. Above 5,000 meters, only mosses and lichens survive. The park receives about 40,000 trekkers annually.