Which planet has a big volcano?

Mars is the planet known for having a massive volcano called Olympus Mons. It’s not just big—it’s colossal. Olympus Mons stands around 22 kilometers high, roughly three times the height of Mount Everest, and spans about 700 kilometers across. 

It is classified as a shield volcano, formed by repeated, slow lava flows over millions of years. Mars’s lower gravity, lack of tectonic plate movement, and thin atmosphere allowed this volcano to grow so huge. 

Olympus Mons provides valuable scientific clues about Mars’s volcanic history and internal structure. It also raises interesting possibilities about past geothermal activity and the planet’s potential to have supported life beneath its surface. So, when it comes to planets with giant volcanoes, Mars takes the crown.