New Zealand has just about every kind of landscape squeezed into one country: snowy mountains, deep fjords, golden plains, dense forests, smoking volcanoes and long sandy beaches. That made it perfect for the imaginary world of Middle-earth, which has all of those places too.
Some bits of the films are so famous that the actual locations have become tourist spots. The pretty green hills of the Hobbits' village - the Shire - were filmed on a farm near a town called Matamata. The film crew built the round Hobbit doors and grassy roofs, and the farmer was so charmed that he kept them. You can still visit 'Hobbiton' today.
Other scenes were filmed in places that look almost too dramatic to be real. The deep fjord of Milford Sound, with its towering cliffs and waterfalls, doubled for places in Middle-earth. So did Mount Ngauruhoe, a near-perfect cone-shaped volcano that played the role of Mount Doom.
Making the films took years and thousands of people - costume makers, set builders, special-effects artists, riders, dancers, painters and more. Many of them were New Zealanders. The films were a huge moment for the country: people all around the world finally saw what New Zealand looked like, and many couldn't quite believe it was a real place.