To stand at the base of a giant sequoia tree is remarkable and humbling — an experience few get because of the trees’ remote location. Anyone lucky enough to be in the Bay Area is about a three-hour drive from the nearest grove, while most Americans will endure a very lengthy car or plane trip.

But there’s an unlikely place with tens of thousands of very accessible giant sequoia trees that isn’t remote at all. It’s on another continent some 5,000 miles away in England, sure, but the seeds themselves came from the forest floor right here in California.

Giant sequoias, officially called Sequoiadendron giganteum, are the largest trees on Earth by volume. The biggest sequoia stands 275 feet tall, with a diameter of 36 feet at its base. Don’t confuse them with coastal redwoods (Sequoia sempervirens), which are the tallest trees on the planet. Bark found on a giant sequoia is brittle and red in color compared to darker bark on redwoods, and the two species don’t grow side by side naturally.

The giant sequoias are incredible, mammoth trees that dwarf everything around them, native to the western slope of the Sierra Nevada between 4,000 and 8,000 feet elevation. Because of the devastating effects of intense wildfires driven by climate change, there are fewer left than ever before in just 70 or so naturally occurring Sierra groves. Most of these spectacular trees are found in Sequoia and Kings Canyon National Parks, Yosemite National Park and Calaveras Big Trees State Park.

These trees ended up across the pond when early European explorers took a liking to them. When Augustus T. Dowd stumbled upon what is now known as the North Grove of giant sequoias at Calaveras in early 1852, word of his extraordinary find traveled the world. Though it wasn’t the first grove of giant sequoias discovered by colonists, it does have the honor of being the first place where news of their existence was widely shared.

“None of those got the same notoriety that Augustus T. Dowd did,” said Amber Sprock, spokesperson for California State Parks’ Central Valley District. “That’s the one that caught everyone’s attention for whatever reason. That’s how they became known to the world.”

Soon after, some of the biggest trees in California were cut down and shipped to the East Coast for exhibition, some were burned and others hollowed out so vehicles could pass through them. Logging across the Sierra removed roughly a third of the sequoias.

But just as California was losing its precious trees, another country was about to start planting them by the thousands. William Lobb, a “seasoned plant collector” from England, first learned of the sequoias on a trip to San Francisco in 1852. He raced to Calaveras and was stunned at what he saw, collecting “seed, shoots and seedlings” before boarding a boat bound for Europe.

While Lobb was one of a few entrepreneurs who began bringing the seeds back to the U.K., his work for a private horticulture company connected him directly with the upper crust of society — including Queen Victoria herself.

“They were looking for any unusual plants,” said Martin Caxton, a member of the Calaveras Big Trees Association. “They simply went all over the world, using the routes in the British Empire.” Thus, the seeds, which weren’t cheap, became popular as centerpieces and accent pieces in neatly trimmed gardens all over the U.K.

They were a favorite of so-called “stately homes,” castles and the like. “My understanding is they became a status symbol in European gardens,” Sprock said.

Giant sequoias are more than just a hobby for Caxton. The 68-year-old U.K. resident became enthralled with the mammoth trees on his first trip to Calaveras more than two decades ago. He’s been coming almost every year since then and now helps with Calaveras educational programs and preservation efforts.

Given his familiarity with Calaveras and his fascination with the big trees, Caxton was surprised to see a picture of a giant sequoia tree during a visit to the University of Oxford in 2003. It’s widely known that there are coastal redwoods in the U.K. (also shipped overseas), but Caxton hadn’t heard of giant sequoias there. As it turned out, they were hiding in plain sight all along.

More than 10,000 giant sequoias are believed to be growing in Europe. The oldest of these giant sequoias are about 170 years old, while others in the U.K. are about a century old, and most are in various states of growth that haven’t developed into the older California sequoias we know and love.

“In that 150-year range, typically they aren’t mature and they don’t have that traditional broccoli look,” Sprock said. “They’re big. But they just look like big trees right now as opposed to that classic giant sequoia look. They’re very spire-shaped when they’re younger.”

Caxton himself has “at least seven” growing within a mile of his house, including one right next to his local pub. “Most people aren’t aware of how they got here or that they’re not natural,” he said. “They just see these trees. They’re a bit bigger than the local trees, but unless you were looking for them you wouldn’t know that.”

It’s not just in the U.K., either. There are unnatural giant sequoias derived from California seeds literally everywhere in Europe: Wales, Scotland, Belgium, Germany, France, the Netherlands, Switzerland, Sweden, Hungary, Austria, Slovakia, Italy and Spain, to name some of the countries with multiple trees. There are also giant sequoias in Australia and New Zealand.

“The European aristocracy were all talking to one another and visiting each other. I would be astonished if Queen Victoria didn’t take [seeds] with her when she visited her relatives in other European countries,” Caxton said.

But while they’ve become a beloved part of the U.K. landscape and could grow as old as California’s most mature sequoias, the trees may not sprout entire giant sequoia forests around them. “The real issue is whether they have a future,” Sprock said. 

That’s because giant sequoia trees are fire dependent.

“They’re sun hogs,” she explained. “Fire plays a role in opening up the canopy so they can get enough sunshine. Fire’s role is both creating space, creating mineral soil and then allowing the seeds to disperse. Fire makes it so the cones open and the seeds actually disperse into the soil. That’s what allows these seedlings to pop up after a hot enough fire.”

The trees growing across the U.K. and the rest of Europe now will continue to do so because most were planted outside of forests in sun-heavy settings like gardens and front lawns. But it’s their seeds that won’t ever get the elements they require after falling into the gardens they inhabit. There’s no naturally occurring fire in those locations — at least, not right now. That’s especially true in the U.K., where it’s wet and mild with cold winters and reasonably warm summers.

“It’s exciting to think about giant sequoias as world travelers,” Sprock said.