An excellent example of the original Scottish Baronial architecture, the great seven-storey castle was completed in 1626 by the Aberdonian merchant William Forbes, ancestor to the "Forbes-Sempill family" and brother of the Bishop of Aberdeen, Patrick of Corse. Forbes purchased the partially completed structure from the impoverished Mortimer family in the year 1610. Forbes' nickname was Danzig Willy, a reference to his shrewd international trading success with the Baltic states. Designed in the L plan, as was Muchalls Castle, which is located in the same region, Craigievar is noted for its exceptionally crafted plasterwork ceilings. Craigevar, Muchalls Castle and Glamis Castle are generally considered to have the three finest ceilings in Scotland. The Clan Forbes family were close friends of the Clan Burnett of Leys, who built both Crathes Castle and Muchalls Castle. The ceilings feature plaster figures of the Nine Worthies and other family emblems. By the early 19th-century, the tower had fallen into decay. Sir John Forbes had considered demolishing the tower and consulted the Aberdeen city architect John Smith who advised against that course of action, stating the tower was: "one of the finest specimens in the Country of the age and style in which it was built." Roof repairs were undertaken and involved the re-construction of almost all of the top floor. The windows, external harling and pointing were replaced and it is likely Smith also designed the gardener's cottage. The castle originally had more defensive elements including a walled courtyard with four round towers; only one of the round towers remains today. In the arched door to that round tower are preserved the carved initials of Sir Thomas Forbes, William Forbes' son. There is also a massive iron portculis or gate covering the entrance door which is named a yett.