This is a constituent made up of a preposition - the head noun phrase : e.g. up + the junction, round + the corner, into + the valley of + death.
a phrase that begins with a preposition and includes a noun or pronoun that is the object of the preposition.
a phrase headed by a preposition, a word such as on, in, between. Prepositions combine with other constituents (usually noun phrases) to form prepositional phrases, as in The man sat on the bench.