Unfortunately, http://elderscrolls.wikia.com/wiki/Mythic_Dawn_Robes_%28Skyrim%29, but not which one. Thing is, my lockpicking and sneaking aren't the best. Furthermore, it seems there's one house that requires a key to access it.

Anyone willing to investigate? I thought they looked pretty cool last game, and in the unlikely event the wiki can be trusted, it seems to have a pretty good effect, too.

Im sure its in the house with the Mythic Dawn flags hanging all over it.....

Youll be directed to them eventually with a quest.
Thats how I found em

Might I ask how I start the quest? Is it in Dawnstar? Or is it started somewhere else?

A messenger appraoched me as I left Winterhold.
Quite sure its random. Probably level dependant.
The quest itself directed me to Dawnstar.

'You are invited to this and this there and there."

Are you serious? I didn't have to do anything with that. I just

Spoiler

did the dark brotherhood quests and got it when (massive spoiler)

Spoiler

the leader admitted to betraying me and gave it to me to kill her with

Edit: I had it confused with something else.

I do not know.
I have not done the quest, only accepted the invitation and listened to what he had to say.

Quest journal confirmes it though it goes:

Do you happen to recall which house it was?

A courier gave me a note in Winterhold.
It directed me to the museum.

So, the robes are in a museum in Dawnstar?

I suppose youll get the note when you have the level

Is it really that hard to just say which building it is? Because I can't find anything resembling a museum in Dawnstar at all. Am I right in just assuming it's the house that needs a key?

Oh that quest is for him. I just ignored it, because I wasn't interested in going to a random museum.

So...the museum physically does not appear until you reach level 20? Because I've stripped the roads bare and there's literally no building labeled as a "museum". Nor are there any nearby buildings.