If you're referring to the fallen angels of the Judeo-Christian tradition they are exactly where God put them when he condemned them; chained and buried in the bowels of the Earth. They are certainly not in hell, as hell as a concept did not exist even in the time of Jesus. It's an early medieval invention. read more
Fallen angels are imprisoned in the ice of Antarctica. It says in the Bible that in the second coming of Christ it will be as it was in the beginning. I would like to point out that the fallen angels were not imprisoned on Earth in the beginning. Now, realize that the ice in Antarctica is melting faster and faster. read more