Safe Rests take place in a safe location designated by your GM, typically lodging at an inn overnight—but could also be at a secret oasis, a well-stocked cabin in the woods, near a sacred shrine, or the like. Camping in the open wilderness or in a dungeon is not sufficient for gaining the benefits of a Safe Rest.
After a Safe Rest, heroes recover all of their HP, Hit Dice, mana (and other class-specific resources), and heal 1 Wound. Safe Rests are a great opportunity for downtime activities as well.