Marble House on Newport's Bellevue Avenue didn't just raise the bar for Gilded Age excess: it demolished it. Built between 1888 and 1892 for William K. and Alva Vanderbilt, it cost $11 million, nearly two-thirds of which went on 500,000 cubic feet of marble. It was the first of Newport's conspicuously extravagant summer cottages.

Behind it was Alva, who had strong-armed her way into Caroline Astor's "400" by throwing a rival ball costing $5 million in today's money for a single night. The house required 36 staff to run for six to eight weeks a year. After divorce and remarriage, Alva reopened it not for parties but for suffrage meetings, turning a monument to wealth into a platform for women's rights.

VoiceMap's self-guided audio tours use Marble House to trace Alva's arc from Gilded Age social climber to suffragist, revealing how one woman's ambition reshaped Newport's skyline and American society.