Question 1

Where is Naoshima Dam?

Accepted Answer

Naoshima Dam is in Naoshima, Kagawa, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of Summer Pockets does Naoshima Dam appear in?

Accepted Answer

Naoshima Dam appears in EP3 of Summer Pockets.

Question 3

Can I visit Naoshima Dam?

Accepted Answer

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

Question 4

Where was Summer Pockets filmed?

Accepted Answer

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