|Location Map ( geo)|
|To:||Whinny Hill (NS368704)|
|Distance:||5.4 miles (8.7 km)|
|Meets:||B790, B789, C18 (Inverclyde)|
|Route outline (key)|
The C18 contains two distinct sections. The first section starts on the B790 east of Houston and ends on the B789 north of the same village. The second section of the road commences a little further south on the B789 and travels westwards. After travelling through a couple of miles of open countryside the C18 meets the council boundary just short of road's descent into Kilmacolm.