works at the college/ in the college

[sri_india]

Sir,
Another query about in/at.
Which of the following expressions is more idiomatic/grammatical?
1. He works as a professor of English at XX college.
2. He works as a professor of English in XX college.

Pl. explain.
Thanks in advance.

[Alan]

In British English 'at' would be used, although American speakers might use 'in'. Overall, 'at' is more likely to be acceptable.