Abandoned House (Anvil)

There are two Abandoned Houses in Cyrodiil.

Anvil
The Abandonded House in Anvil is where you can meet The Stranger in the quest Taking Care of Lex.

Cheydinhal
The Abandone House in Cheydinhal is located along the west wall near the Great Chapel of Arkay. The basement houses the door to the Dark Brotherhood Sanctuary though you won’t be able to open it until Lucien Lachance tells you the password after completing the A Knife in the Dark mission.