Few patrician houses are open to the public along the Herengracht, so make a beeline to this mansion to see Grachtengordel (Canal Ring) luxury at its best. In 1895, the widow Sandrina Louisa Willet-Holthuysen donated the house and contents -- which included her husband's extensive art collection -- to the city of Amsterdam. Visitors can wander through this 17th-century canal house, now under the management of Amsterdams Historisch Museum, and discover all its original 18th-century interiors, complete with that era's mod-cons: from ballroom to cabinet des merveilles (rarities cabinet). Objets d'art of silverware, glass, and goldsmith's work accent the rooms. The biggest salon is the Blue Room, handsomely decked out in blue Utrecht velvet, a ceiling painted by Jacob de Wit, and porcelain bibelots. Note the gilded staircase, whose walls are painted in faux-marble. You can air out the aura of Dutch luxury by lounging in the French-style garden in the back. For a peek at the Downstairs side to this Upstairs coin, be sure to check out the wonderful kitchen. COST: EUR4.