This question is about the use of preposition 'at'.
In this passage:
In 715 CE, ten years after the foundation of the Umayyad Mosque at Damascus, the Umayyad Caliph Al-Walid engaged in the construction of the mosque that was to equal the former.
Why did they use "at"? I think it should be replaced by "in", I am confused.
This passge is taken from muslimheritage.com, and I'm studying the translation of it into Arabic in my university.