Help with strage place in "The Reach"

Tex_lg

Hello everyone! During my travels I have noticed this strange place located in The Reach. Can anyone tell me if it's reachable or is it part of a quest?
(screenshots)
https://ibb.co/my4Cvs7
https://ibb.co/xsCrRWh

amig186

It looks like the same building as the Blades temple in TES V Skyrim, which is also located in the Reach. Unfortunately, it's out of bounds according to UESP, so you can't go there.

Soarora

It’s Sky Haven Temple. Like amig said, it’s reachable in TES 5 but not in ESO. I’ve tried haha.

Beilin_Balreis_Colcan

We can even see it from the N Markarth wayshrine. If you look in the exact direction of the temple, you'll see what looks like a pointed temple roof, partly obscured by heavy mist. I also tried to get up there, but the mountainside is too steep.

SeaGtGruff

I never noticed this before. Cool! I'll go check it out later.