Question 1

Where is Katakurakan?

Accepted Answer

Katakurakan is in Suwa, Nagano, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of mono does Katakurakan appear in?

Accepted Answer

Katakurakan appears in EP3 of mono.

Question 3

Can I visit Katakurakan?

Accepted Answer

Yes. Katakurakan is a real place you can visit. Check what it looks like on Street View before you go.

Question 4

Where was mono filmed?

Accepted Answer

Anime and manga are not filmed the way live action is. Their backgrounds are painted from photographs of real locations, and Katakurakan is one of those real places (EP3).