5 photos$18,500,000list price
Per sq ft$8,204
4 bd · 4.5 ba · 2,255 sq ft House
631 N MASHTA DR #33149, KEY BISCAYNE, FL 33149
Listing courtesy of Coldwell Banker. MLS# B26058354.On the MLS · Listed Jul 29
$18,500,000
520 S MASHTA DR #33149, KEY BISCAYNE, FL 33149
5 beds4 baths3,085 sq ftHouseBuilt 1961
Updated today, November 3, 2026This home against Key Biscayne
$5,997 per sq ft, 393% over the Key Biscayne median
85 days on the market
Price cut $1,400,000 since it was listed at $19,900,000
$201,741 in property taxes (2026)
22,216 sq ft lot
Private pool
Waterfront
2 car garage
Key Biscayne today: 129 homes for sale, median list price $2,725,000.
About this home
Seize a rare opportunity to create a landmark waterfront estate on one of the largest residential lots in Key Biscayne’s exclusive Mashta Island enclave. Spanning an extraordinary 22,140 square feet, this exceptional property offers 138 feet of pristine water frontage and sweeping open water views, providing an unparalleled setting for a world class residence.Plans by renowned architect, Pablo Corazzini of Vitalini Corazzini Architects, are available to the buyer, offering a thoughtfully conceived vision that takes full advantage of the property’s remarkable scale, premier waterfront setting, and spectacular sunsets. The proposed design creates an extraordinary canvas for sophisticated indoor-outdoor living and entertaining, should the buyer choose to pursue the concept.With its exceptional lot size, expansive water frontage, and coveted Mashta Island address, this is a truly irreplaceable opportunity to create a legacy estate in one of South Florida’s most prestigious waterfront communities.
Zoned schools
Elementary: Key Biscayne K-8 Center
Middle: Ponce de Leon Middle School
High: Coral Gables Senior High School
From Miami-Dade County Public Schools attendance zones.
Listing courtesy of Coldwell Banker Realty. MLS# A12071221.
Listing information is provided by the MLS and is deemed reliable but not guaranteed.
Listed August 10, 2026.
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