Dundonald Castle commands impressive views and, in its main hall, has one of the finest barrel-vaulted ceilings preserved in Scotland. It was the first home of the Stuart kings, built by Robert II in 1371, and reckoned to be the third most important castle in Scotland in its time, after Edinburgh and Stirling. The visitor centre has good information on prior settlements, and scale models of the castle and its predecessors. Buses running between Troon and Kilmarnock stop in Dundonald.
There are ongoing archaeological investigations here that, it is hoped, will reveal remains of an earlier castle.
Winter opening hours are changeable; call ahead.