How would the ponies react in this kind of circumstance?

[Newman1651 35]

Something about a region in Equestria where the "Ancient" ruins of a Human city stands. the identity of this city, based on whatever landmarks are still intact or unburied being Canterlot City from the Equestria Girls spin off:

The general presentation of the ruins being similar to how Adventure time depicted ruins of Pre-Mushroom War era Human civilization. That being, the geography of the land has changed resulting in many of these ruins either awkwardly sticking out of the ground at odd angles or being found in odd and unusual places. a large amount of the time, it's underground. Sometimes sections of the city would be aboveground with very little damage.

What destroyed the city (or brought it into equestria and was consequentially destroyed) is unknown, though it seems to be magic-related.

characters included are the Mane Six, the Princesses, Shining Armor, Starlight Glimmer, and Sunburst. The identity of the ruins largely remained a mystery until very recently. Thanks to some good old fashioned Amateur archaeology.

 

I understand that the human world and equestria are two separate dimensions, but this is based on old disproven headcanons of Equestria being on a post apocalyptic or posthuman Earth.

 

 

[EpicEnergy 23,240]

They would react very curious, and would be eager to learn more about who inhabited the city.