sentences:  The route crosses no major watercourses, although creeks adjacent to or spanned by the route drain into the Pazinčica and Boljunčica rivers, or directly into the Adriatic Sea in the case of watercourses flowing down Učka's eastern slopes.The Učka Tunnel contains a spring discovered during its construction and used for the water supply of Opatija ever since.The route runs through an area subject to significant air temperature variations.