A prepositional phrase can work as an adjectival phrase or as an adverbial phrase. An adjectival phrase is the one that modifies a noun or a pronoun usually by describing it. An adverbial phrase is the one that modifies an adjective, an adverb, or a verb by answering questions such as when, how, or where. In this case, the underlined prepositional phrase is used in the sentence as an adverbial phrase because it is providing information about place.