Difference between IN and AT as a place preposition

Question

Which one is more usual: "The first Thanksgiving celebration was first organised IN Plymouth Rock" or "AT Plymouth Rock"?

Answer 1

Plymouth Rock is the traditional site of disembarkation of William Bradford and the Mayflower Pilgrims who founded Plymouth Colony in December 1620.

An image of the rock is shown in the link.

https://en.m.wikipedia.org/wiki/File:Plymouth_Rock,_Plymouth,_MA,_jjron_03.05.2012.jpg

We use at: to refer to a position or location which we see as a point.

We use in: to talk about locations within a larger area.

reference

In our case here, at should be more appropriate.

I edit to give a perspective of the rock size.

In its present state, Plymouth Rock weighs approximately 10 tons, including both the upper and lower parts. In 1620 it was much larger: estimates range from 40 to more than 200 tons.

https://www.britannica.com/topic/Plymouth-Rock-United-States-history