A large part of Antrim is very hilly. The highest hills are in the east of the county. The mountain range runs north and south, and, following this direction the highest points are Knocklayd , Slieveanorra , Trostan , Slemish , Agnew's Hill and Divis . Along the coast there are a lot of cliffs in the north. Some of the most remarkable cliffs are those formed of vertical basaltic columns, like at the Giant's Causeway.