Some of the biggest, oldest, hottest and longest things on Earth sit inside United States national parks, and the National Park Service (NPS) describes them in its own words. Five are collected here with the figures kept as the NPS pages give them. Where two NPS pages disagree on a number, this guide says so or leaves the number out. Every page was read on 26 October 2026.
1. The General Sherman Tree: the biggest tree by volume
The NPS page for Sequoia and Kings Canyon National Parks calls the General Sherman Tree the largest tree, by volume, in the world. It estimates that the trunk alone weighs nearly 1,400 tons, which the page compares to about 15 adult blue whales, and that the tree probably holds 630,000 board feet of lumber, enough in the page’s words to build 120 average-sized houses.
The exact volume is given as 52,500 cubic feet on that page and 52,508 cubic feet on a separate NPS list of the largest trees, so this guide treats it as roughly 52,500 cubic feet. The list ranks trees by trunk volume only, with General Grant second. It adds that when scientists measured the President Tree in 2011 and 2012 and counted branch volume as well as trunk volume, the President Tree came out second and Grant third.
In September 2021 the General Sherman Tree was one of numerous giant sequoias wrapped in a protective aluminium material while a lightning-caused wildfire burned towards Giant Forest.
2. Bristlecone pines: the oldest non-clonal species
Great Basin National Park describes the Great Basin bristlecone pine as the oldest non-clonal species on the planet. Its page adds that clonal organisms such as the quaking aspen and the Mojave Desert creosote are considered much older, because they grow new trees or bushes from their root systems. An aspen grove called Pando in Utah is estimated at around 16,000 years old.
One bristlecone became famous after it was gone. In 1964 a geographer named Donald Currey was studying bristlecone rings beneath Wheeler Peak. The NPS says accounts differ on how a tree known as Prometheus met its end, but that Currey had Forest Service permission to have it cut down. Counting its rings later revealed 4,862 growth rings, and the NPS says that in such harsh conditions a ring likely did not form every year.
Estimates of Prometheus’s age vary between NPS pages (about 4,900 years on one, between 4,700 and 5,200 years on another), so this guide quotes the ring count instead. The park says there is a good chance that older bristlecone pines have not yet been dated, and a slab of Prometheus can be seen at the park’s visitor centre.
3. Death Valley: a salt flat below sea level and a world-record temperature
Badwater Basin in Death Valley National Park is the lowest point in North America, at 282 feet (86 metres) below sea level. The NPS says its salt flats cover nearly 200 square miles and are composed mostly of table salt, with calcite, gypsum and borax. The pool there is home to an endemic snail found naturally only at that location.
Look up and the scale changes. The page points out a sign high on the cliffs of the Black Mountains marking sea level, and Telescope Peak, at 11,049 feet (3,368 metres), is described as over two miles above a visitor standing at Badwater.
The park’s FAQ page gives the other headline number: a world-record highest air temperature of 134 degrees Fahrenheit (57 degrees Celsius), recorded on 10 July 1913 at Furnace Creek Ranch.
4. Mammoth Cave: the longest known cave, joined up in 1972
Mammoth Cave in Kentucky is described by the NPS as the longest known cave in the world. Its total mapped length keeps growing, and NPS pages published in different years give different totals: 420 miles in a September 2021 news release and 426 miles in an article last updated in September 2022. The 2022 article says the exact length is still unknown, so no single total is claimed here.
One documented jump in length came on 9 September 1972. Before then, the Flint Ridge cave system had 86.5 miles of mapped passageways and the Mammoth Cave system had 57.9 miles. A team of six entered through the Austin Entrance, and when leader John Wilcox crawled on ahead he shouted, “I see a tourist trail!” The two systems were joined into one of 144.4 miles.
The NPS says prehistoric American Indians first entered around 5,000 years ago, and that Stephen Bishop, an enslaved Mammoth Cave guide, extended the known length and made one of the first maps in the 1840s.
5. Mauna Loa: the largest active volcano on the planet
The NPS Hawaiʻi Volcanoes pages call Mauna Loa the largest active volcano on the planet. One page says it makes up roughly 51% of Hawaiʻi Island, and another notes that its summit is slightly lower than neighbouring Mauna Kea but that Mauna Loa has a much greater volume. The shield volcanoes page gives the width of its base on the sea floor as about 100 miles.
Height is where the NPS pages part company. They give the summit as 13,681 feet on one page and 13,677 feet on another, and the height from the sea floor as about 30,000 feet on one page and almost 33,500 feet on another, so no height is quoted here as settled. The NPS notes that Mauna Loa erupted in 2022 for the first time in nearly 40 years.
The bottom line
The NPS describes the General Sherman Tree as the world’s largest tree by volume, bristlecone pines as the oldest non-clonal species, Badwater Basin as the lowest point in North America, Mammoth Cave as the longest known cave and Mauna Loa as the largest active volcano. Where its pages give different numbers, they are flagged above. For more places that look almost too incredible to exist, see 3 Real Places That Look Almost Too Incredible to Exist.
Sources
- The General Sherman Tree, Sequoia and Kings Canyon National Parks, NPS, page last updated 25 November 2025 (nps.gov)
- The Largest Trees in the World, Sequoia and Kings Canyon National Parks, NPS, page last updated 23 November 2023 (nps.gov)
- Bristlecone Pines, Great Basin National Park, NPS, page last updated 16 May 2026 (nps.gov)
- The Prometheus Story, Great Basin National Park, NPS, page last updated 5 January 2021 (nps.gov)
- Badwater Basin, Death Valley National Park, NPS, page last updated 7 January 2026 (nps.gov)
- Frequently Asked Questions, Death Valley National Park, NPS, page last updated 15 August 2026 (nps.gov)
- Exploring the World’s Longest Known Cave, NPS, page last updated 7 September 2022 (nps.gov)
- Mammoth Cave National Park Adds New Miles to Cave Length, NPS news release of 11 September 2021 (nps.gov)
- Mauna Loa, Hawaiʻi Volcanoes National Park, NPS, page last updated 30 November 2022 (nps.gov)
- Shield Volcanoes, NPS, page last updated 17 April 2023 (nps.gov)