From Bulbapedia, the community-driven Pokémon encyclopedia.
The Gilded Hall is a special area in Pokémon Mystery Dungeon: Gates to Infinity. It replaces the Golden Chamber of previous games in that both have a golden appearance, contain valuable items, and do not have a straightforward method of access. The Gilded Hall can be accessed in a fashion similar to Mapless Streets, with the player being randomly warped into the Gilded Hall by a mysterious power. However, unlike Mapless Streets, the Gilded Hall has floor numbers.
The Gilded Hall contains different Pokémon depending on what dungeon the player was in before entering the Gilded Hall. Sparkling Floor tiles often hold Gold Ribbons, and Poké can be found in relatively large quantities.
Unlike the Golden Chamber, the Gilded Hall changes floor layouts just like normal dungeons. It also contains traps and enemy Pokémon, and may even contain a monster house.