Adding glitz to a Laurel Hollow manse

What makes the Art Deco-inspired designer show house opening tomorrow in Laurel Hollow even better is knowing what lies beneath the home's three sumptuously decorated floors.

A secret door in the powder room off the grand foyer of the circa 1930 Georgian-esque mansion leads downstairs to a space believed to have once been a speakeasy. Its remnants in the dark and cavernous basement would fascinate any historical house lover -- cobwebbed bottles of booze, a door in the floor that might have once led to a tunnel connecting the property to Cold Spring Harbor, a mysterious space plastered with vintage Alberto Vargas pinup girl prints, what looks to be a Prohibition-era safe room. Visitors will have to imagine what's downstairs and enjoy the thought -- the space is off limits for insurance reasons.

The underground details add to the period romance of Cedar Knolls, which gets a decorator touch as its owners try to snag a buyer for the home, priced at $2.495 million. Straddling what once was the Louis Comfort Tiffany Laurelton Hall estate and a property where John Lennon used to summer, Cedar Knolls was built for railroad magnate Jay Gould's grandson and was designed by the architectural firm that worked on the Whitney Museum of American Art's Greenwich Village site.

Many of the 26 decorators found inspiration in the Gold Coast era while designing the rooms. Here are some of the trends that emerged, straight up.