Jupiter's moon Io is covered in active volcanoes. Now we have the 1st map of them 

 Jupiter's moon Io, the most volcanically active world in the solar system, may possess a global ocean of magma underneath its surface, as well as mysteriously warm poles, a new study finds. 

https://cdn.mos.cms.futurecdn.net/qLbsfuSanAtkn6HMp6Hny3.jpg

https://www.space.com/jupiter-moon-io-volcanoes-map