Wow! What a great experience again.
You are one of the amazing travelers we have around here. You take your time to enjoy almost everything on offer wherever the journey takes you.. Lol

If you and a friend stand at opposite ends of the underpass and one of you speaks towards the wall at a normal volume, the other person can hear you perfectly even though you are almost thirty two feet away and facing in the opposite direction. The stone walls and ceiling reflect the sound on a path across to the opposite side of the underpass.

The echo you mentioned look magical. Lol

It does not have regard for distance.... Hahahahab

If I end up in UK, Grand Central Terminal would top the list of places to visit. I want to experience the magical echo myself... Lol

Thanks bud for the update.