Does the particle に in に作られた mark the agent or the location here?

Question

I'm confused about 「に作られた」 in the following sentence. Kindly explain this part to me.

「Central Base」とは、旧「アクアポリス・中央エアポート」に作られた、「ASDF」の陸上（？）基地のことだ。

Some sort of translation:

1. Central base is, created by the old Aquapolice - Central airport, ASDF's land(?) base.

2. Central base is, created on the old Aquapolice - Central airport, ASDF's land(?) base. (However in this case I think that で would be more suitable)

The "（？）" is part of the original text.

Answer 1

The reading as に to mark the agent of the passive construction is definitely syntactically possible, but a much more likely reading is the locative に, i.e. your second reading.

Why is it に and not で? で marks a place where an action happens, に marks a place where something "exists". There is definitely some overlap in usage, but で in this case sounds strange to me, as if "it was built there, but then moved somewhere else".