From Bulbapedia, the community-driven Pokémon encyclopedia.
The House of Memories (Japanese: たましいのいえ Soul House), named Soul House in Generation II, is a small building located in Lavender Town in the region of Kanto during the events of the Generation II games and Pokémon HeartGold and SoulSilver. It is located in the southeast portion of Lavender Town, where the Poké Mart was during the events of the Generation I games and Pokémon FireRed and LeafGreen.
The House of Memories was built to hold graves from the Pokémon Tower when it was converted to the Kanto Radio Tower. There are many chambers within the building, but they cannot be accessed by anyone other than Mr. Fuji. There are no wild Pokémon or Trainers found within the House of Memories.
In HeartGold and SoulSilver, if the player stays in the House of Memories for too long and then talks to their walking Pokémon, a message saying that it either "appears somehow sad" or "is trembling with fear" appears, with the Pokémon eventually becoming angry at the player.
"May the Souls Of Pokémon Rest Easy"GSC, "May Pokémon Spirits Rest Easy"HGSS