genius loci

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The distinctive atmosphere or pervading spirit of a place.
2. n. The guardian deity of a place.

Wiktionary

1. n. The spirit or one of the spirits presiding over or guarding a particular place, such as a glade or pool.
2. n. The geist, distinctive atmosphere, or characteristic spirit of a place, especially when regarded as an artistic muse.

GNU Webster's 1913

1. n. the genius or presiding divinity of a place; hence, the pervading spirit of a place or institution, as of a college, etc.

WordNet 3.0

1. n. the special atmosphere of a place
2. n. the guardian spirit of a place