Question 1

Where is Hydrangea Stairs?

Accepted Answer

Hydrangea Stairs is in Koto, Tokyo, Japan. You can see its exact position from the map coordinates and the Street View link.

Question 2

Which scene of Digimon Adventure tri. Reunion does Hydrangea Stairs appear in?

Accepted Answer

Hydrangea Stairs is a real place that appears in Digimon Adventure tri. Reunion.

Question 3

Can I visit Hydrangea Stairs?

Accepted Answer

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

Question 4

Where was Digimon Adventure tri. Reunion filmed?

Accepted Answer

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