The A78 is an A road in Scotland. It connects Greenock and Prestwick on a route which follows the northern section of the Ayrshire coast.

Prestwick is a town in South Ayrshire on the west coast of Ayrshire in Scotland about 30 miles southwest of Glasgow. It adjoins the larger town of Ayr to the south on the Firth of Clyde coast, the centre of which is about two miles south, and the small village of Monkton to the north. It had a population of 14,901 at the 2011 census.