Question: Maple Hill in Sussex County, N.J. lies on which interstate hiking trail?
Sentence (from "Hiking trail of the Piusa River"): The hiking trail is situated on Piusa River Valley Landscape Protection Area and among the most interesting sights on the trail are castle ruins, sandstone outcrops Härma Mäemine wall or Keldri wall (highest sandstone outcrop in Estonia), Härma alumine wall or Keldri wall and several old mill places.
Relevant evidence: No