In the summer there is a small stone jail for those who are caught breaking the rules of the Sorcery Springs Geyser Basin, but in winter they are imprisoned within the warm waters themselves. No bolts or bars are needed, the cold takes the place of prison walls.
Faerie foods with unusual effects. Like faerie sausages that turn the eaters into wiener dogs, faerie wines that make the drinker whiny, etc. There's a table in Palladium Fantasy RPG which has a table of ideas.