Happy Hearth Inn is a small hotel located at Hyrule Town in The Minish Cap.
It is only accessible after Link completes the Cave of Flames. Like Link's House, Link is able to sleep at the Inn and recover his hearts. Link receives a Kinstone whenever he stays at the Inn.
Link finds Nayru, Din, and Farore at the Inn. By fusing Kinstones with them, Link starts their side quest, the end of which leaves only one of them left at the Inn due to there only being two houses available.
On the balcony of the second floor is a Treasure Chest. It is only accessible after completing the Temple of Droplets and contains 200 Rupees.