To punish Loki for the crimes he had commited, including killing Odins son Balder, the gods tied him up in a cave with one of his sons insides. A giantess hung a large snake over Loki and when a drop of the snakes poison dropped onto Lokies face he would twist in pain so the hole world shook.
This is a replica of that cave. It lies in Malmös slottspark, Sweden. It’s so convinient being a Avengers Loki fan and Swedish.