Skyrim Dawnstar Black Door. I was doing a new playthrough and was doing the DB questline as usual. Complete unofficial game guide and wlakthrough to The Elder Scrolls V: Skyrim.
The entrance is a black door similar to the door to the sanctuary in Falkreath. The Black Door, also known as Black Doors, serve as entrances to the Dark Brotherhood Sanctuaries across Tamriel. The Black Door in Cheydinhal asks, "What is the color of night?" with the answer being: "Sanguine, my brother." Skyrim Dark Brotherhood - Upgrade the Dawnstar Sanctuary.
Picking any of the three choices made the same voice that asked Depneds there is one for the dark brotherhood the answer is silents.
It is built into the rock face on the northern coast of Dawnstar with several nightshade plants growing around the entrance.
The Black Door, also known as Black Doors, serve as entrances to the Dark Brotherhood Sanctuaries across Tamriel. They are guarded by different verbal passcodes in the form of riddles. But this answer isnt available untill you have completed the questchain mentioned earlier.