520 S Mashta Dr Key Biscayne FL 33149 | MLS #A12071221
520 S Mashta Dr
Key Biscayne, FL, 33149
$19,900,000
5 Beds
4 Baths
3,085 SqFt
0 Acres
$19,900,000
520 S Mashta Dr
Key Biscayne, FL, 33149
MLS #A12071221 image #0MLS #A12071221 image #1MLS #A12071221 image #2MLS #A12071221 image #3MLS #A12071221 image #4MLS #A12071221 image #5MLS #A12071221 image #6MLS #A12071221 image #7MLS #A12071221 image #8MLS #A12071221 image #9MLS #A12071221 image #10MLS #A12071221 image #11MLS #A12071221 image #12MLS #A12071221 image #13MLS #A12071221 image #14MLS #A12071221 image #15MLS #A12071221 image #16MLS #A12071221 image #17MLS #A12071221 image #18MLS #A12071221 image #19MLS #A12071221 image #20MLS #A12071221 image #21MLS #A12071221 image #22MLS #A12071221 image #23MLS #A12071221 image #24MLS #A12071221 image #25MLS #A12071221 image #26MLS #A12071221 image #27MLS #A12071221 image #28MLS #A12071221 image #29MLS #A12071221 image #30MLS #A12071221 image #31MLS #A12071221 image #32MLS #A12071221 image #33MLS #A12071221 image #34MLS #A12071221 image #35MLS #A12071221 image #36MLS #A12071221 image #37
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.

Property Details

Price:
$19,900,000
MLS #:
A12071221
Status:
Active
Beds:
5
Baths:
4
Type:
Single Family
Subtype:
Single Family Residence
Subdivision:
MASHTA ISLAND A REPLAT OF
Neighborhood:
mashtaislandareplatof
Listed Date:
Aug 12, 2026
Finished Sq Ft:
3,085
Total Sq Ft:
4,177
Year Built:
1961
WaterfrontPoolMashta Island A Replat OfMashtaislandareplatofMashta Island A Replat OfKeybiscaynePonce De LeonCoral GablesOk To Lease

Schools

Elementary School:
Keybiscayne
Middle School:
Ponce De Leon
High School:
Coral Gables

Interior

Appliances
Other Equipment/Appliances
Bathrooms
4 Full Bathrooms
Cooling
Central Air
Flooring
Tile
Heating
Central
Interior Features
First Floor Entry, Split Bedroom, Family Room

Exterior

Architectural Style
Attached, One Story
Community Features
Other Subdivision – See Remarks
Construction Materials
Concrete Block Construction
Covered Spaces
2
Direction Faces
East
Garage Spaces
2
Lot Features
1/2 To Less Than 3/4 Acre Lot
Open Parking YN
1
Parking Features
Driveway
Roof
Barrel Roof, Curved/S-Tile Roof
View
Bay, Direct Ocean
Waterfront Features
Ocean Access, Seawall

Financial

Tax Year
2026
Taxes
$201,741
Need more info?
Ask a Question
Ready to go see it?
Schedule a Showing

Mortgage Calculator

 

Map

Current real estate data for Single Family in Key Biscayne as of Aug 18, 2026
42
Single Family Listed
159
Avg DOM
2,688
Avg $ / SqFt
$15,055,976
Avg List Price

Community

Subdivisions in Key Biscayne

Similar Listings Nearby

broker reciprocity
MLS# A12009875broker reciprocity
120 Knollwood Dr
Key Biscayne, FL

$19,950,000

0.6 miles away

broker reciprocity
MLS# A11934196broker reciprocity
100 Cape Florida Dr
Key Biscayne, FL

$19,800,000

0.7 miles away

broker reciprocity
MLS# A11731927broker reciprocity
960 Mariner Dr
Key Biscayne, FL

$19,500,000

0.4 miles away

broker reciprocity
MLS# A11912105broker reciprocity
550 Harbor Dr
Key Biscayne, FL

$19,450,000

0.5 miles away

broker reciprocity
MLS# A11990382broker reciprocity
640 S Mashta Dr
Key Biscayne, FL

$16,800,000

0.1 miles away

broker reciprocity
MLS# A12051668broker reciprocity
161 Cape Florida Drive
Key Biscayne, FL

$14,990,000

0.6 miles away

Property Summary

    Located in the MASHTA ISLAND A REPLAT OF subdivision, 520 S Mashta Dr Key Biscayne FL is a Single Family for sale in Key Biscayne, FL, 33149. It is listed for $19,900,000 and features 5 beds, 4 baths, and has approximately 3,085 square feet of living space, and was originally constructed in 1961. The current price per square foot is $6,451. The average price per square foot for Single Family listings in Key Biscayne is $2,688. The average listing price for Single Family in Key Biscayne is $15,055,976.
520 S Mashta Dr
Key Biscayne, FL