The largest known tree species in the world is the Giant Sequoia (Sequoiadendron giganteum). These majestic trees can reach heights of over 300 feet (about 91 meters) and have massive trunks that can be over 30 feet (about 9 meters) in diameter. They are native to the Sierra Nevada mountain range in California. Giant Sequoias can live for over 3,000 years, making them among the oldest living organisms on Earth. Their impressive sizes and longevity have made them a popular symbol of natural grandeur and conservation efforts.