The family seat of the Stuart Earls of Bute is one of Britain's more magnificent 19th-century stately homes, the first to have a telephone, underfloor heating and a heated pool. Its eclectic interior, with an imposing central hall and chapel in Italian marble, is heavily influenced by the third Marquess' interests in Greek mythology and astrology. The drawing room has paintings by Titian and Tintoretto among other masters. Mount Stuart is 5 miles south of Rothesay; bus 490 runs here hourly.
Buy tickets at the visitor centre (or book online), from where it's a 15-minute stroll (a courtesy bus is also available) through lovely grounds to the house. Entry is either by guided tour or free visit, depending on the time. Private tours (£20 or £40) offer glimpses of the pool and more bedrooms.
There's a cafe serving famously opulent afternoon teas (book ahead).
Discounted ferry-plus-entrance tickets are available from CalMac.