Slains Castle is a ruined castle near Cruden Bay in Aberdeenshire, Scotland, overlooking the North Sea. The huge ruin of New Slains Castle stands perched atop tall, sea-facing cliffs. The castle was constructed around an existing tower house in 1597 by the 9th Earl of Erroll. Significant reconstruction of the castle has been carried out a number of times, lastly in 1837. It was altered in 1664 when a corridor was inserted within the courtyard and again in 1836 it was rebuilt and granite faced. At one time it had three extensive gardens.