The largest volcano in the solar system is Olympus Mons, located on Mars. This shield volcano stands approximately 13.6 miles (22 kilometers) high, making it nearly three times the height of Mount Everest. Olympus Mons has a diameter of 370 miles (600 kilometers) and features a unique caldera at its summit, about 50 miles (80 kilometers) wide. Its enormous size is attributed to the low gravity on Mars, along with volcanic activity that has persisted for billions of years. The study of Olympus Mons provides valuable insights into the geological history of Mars and the potential for past volcanic activity on the planet.