Here's why:
* Adverbs modify verbs, adjectives, or other adverbs. They provide information about how, when, where, or to what extent something happens.
* Adverbs of place specifically tell us the location of an action or state of being.
Examples:
* Here is the book. (Adverb of place modifying the verb "is")
* The cat is outside. (Adverb of place modifying the verb "is")
* I went upstairs. (Adverb of place modifying the verb "went")