Question 1

Where is Matsumoto-jo Castle?

Accepted Answer

Matsumoto-jo Castle is in Matsumoto, Nagano, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of mono does Matsumoto-jo Castle appear in?

Accepted Answer

Matsumoto-jo Castle appears in EP3 of mono.

Question 3

Can I visit Matsumoto-jo Castle?

Accepted Answer

Yes. Matsumoto-jo Castle 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 Matsumoto-jo Castle is one of those real places (EP3).