You might be surprised that a 90-year-old condo at 1325 North Astor Street is being listed for just shy of $8 million — but don’t be, says Realtor.com senior economist George Ratiu. The home is located in the storied Astor Street District, designated a Chicago landmark. “Economically speaking,” says Ratiu, “a historic district generally limits the redevelopment of the buildings within it to retain the character. By direct consequence of that, you end up with a limited supply, which automatically tends to drive prices higher.”

Not to mention that this particular property comes in the form of a two-level 7,900-square-foot penthouse with views of Lake Michigan. It has six bedrooms and three enormous private terraces. The floors — parquet in the 35-by-18-foot living room, herringbone in the 26-by-16-foot dining room, and patterned marble in the round entryway — are all original. But there have been updates: The kitchen, with its floor-to-ceiling curved wall of custom glass-front cabinetry and La Cornue oven range, was overhauled in 2000.

The current owners, Donco Recycling Solutions founder and chairman Robert Mendelson and his wife, Linda, purchased the Gold Coast home nearly 50 years ago and raised their family there, says the listing agent, Nick Kluding of Baird & Warner. The Georgian Revival building was designed in the late 1920s by architect Andrew Rebori, who was also behind Loyola University’s art deco Madonna della Strada Chapel in Rogers Park, the art moderne Frank F. Fisher Apartments in the Gold Coast, and the now-demolished Chicago Riding Club, which later became the WBBM-TV studio.

The limestone duplex penthouse is architecturally distinct from the rectangular brick building it crowns. “Each home [on floors 2 through 12] occupies an entire floor,” says Kluding. “And then this one is the entire top two floors. [From the outside] it looks like a beautiful single-family home has just been kind of airdropped on top.”