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.
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:
$18,500,000
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
See this Listing
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
Map
Community
- Address520 S Mashta Dr Key Biscayne FL
- SubdivisionMASHTA ISLAND A REPLAT OF
- CityKey Biscayne
- CountyMiami-Dade County
- Zip Code33149
Subdivisions in Key Biscayne
- 155 SUNRISE CONDO
- 32 54 42 & 5 55 42,TORPICAL HOMES
- 325 FERNWOOD ROAD CONDO
- 544-548 FERNWOOD CONDO
- 596 Fernwood
- BAHAMA HOUSE SOUTH CONDO
- BAHAMA HOUSE SOUTH CONDO,KEY CASSA
- BAHIA MAR CONDO OF KEY BI
- BISCAYNE KEY ESTATES
- BISCAYNE KEY ESTATES SUB
- BLUE PELICAN CONDO
- CAPE FLA CLUB CONDO CLUST
- CAPE FLA SUB SEC 2
- CAPE FLORIDA CLIB CONDO P
- CAPE FLORIDA CLUB CONDO
- CAPE FLORIDA CLUB CONDO P
- CAPE FLORIDA CLUB CONDO PCape Florida Club
- CAPE FLORIDA CLUB CONDO PCAPE FLORIDA CLUB CO
- CAPE FLORIDA SUB SEC 1
- CAPE FLORIDA SUB SEC 3
- CAPE FLORIDA SUB SEC 3,Village Estate
- CASA DEL MAR CONDO
- CASA DEL MAR CONDO,CASA DEL MAR
- CASA DEL MAR CONDOCASA DEL MAR
- CAY POLYNESIA CONDO
- CAY POLYNESIA CONDO,Cay Polynesia
- CLUB TOWER ONE CONDO
- CLUB TOWER ONE CONDO,THE OCEAN CLUB
- CLUB TOWER THREE CONDO
- CLUB TOWER TWO CONDO
- COMMODORE CLUB EAST
- COMMODORE CLUB SOUTH COND
- COMMODORE CLUB SOUTH CONDCommodore Club South
- COMMODORE CLUB WEST CONDO
- COMMODORE CLUB WEST CONDO,COMMODORE CLUB
- COMMODORE CLUB WEST CONDO,COMMODORE CLUB WEST
- COMMODORE CLUB WEST CONDOCommodore Club West
- CRANDON TOWER CONDO
- G B RESORT CONDO HOTEL
- G B VILLAS
- GALEN BREAKERS CONDO
- GALEN BREAKERS CONDOMINIU,Galen Breakers
- GALEN DRIVE CONDO APTS
- GDNS OF KEY BISC-ALHAMBRA
- GOVERNORS LODGE ASSOC CON
- GRAND BAY RESIDENCES COND
- GRAND BAY RESIDENCES COND,GRAND BAY
- GRAND BAY RESIDENCES CONDGrand Bay
- GRAND BAY RESIDENCES CONDGRAND BAY RESIDENCES
- GRAND BAY TOWER CONDO
- GRAND BAY TOWER CONDOGrand Bay
- GRAND BAY TOWER CONDOGRAND BAY RESORT AND
- GRAPETREE TOWNHOUSE CONDO
- HOLIDAY COLONY
- HURRICANE COVE
- INDIES CONDO
- ISLAND BREAKERS CONDO
- ISLAND HOUSE
- ISLAND HOUSE APT INC – CO
- KEY BISC AMBASSADOR CONDO
- KEY BISCAYNE COMMODORE CL
- KEY BISCAYNE COMMODORE CL,KEY BISCAYNE COMMODO
- KEY BISCAYNE COMMODORE CLCOMMODORE CLUB EAST
- KEY BISCAYNE ONE HUNDRED
- KEY BISCAYNE VI CONDO
- KEY BISCAYNE VI CONDOKEY BISCAYNE VI COND
- KEY BISCAYNES COMMODORE C
- KEY COLONY
- KEY COLONY NO 1
- KEY COLONY NO 1,KEY COLONY
- KEY COLONY NO 1Key Colony
- KEY COLONY NO 1Tidemark
- KEY COLONY NO 2 CONDO
- KEY COLONY NO 2 CONDO,KEY COLONY NO 2 COND
- KEY COLONY NO 2 CONDOKey Colony
- KEY COLONY NO 2 CONDOKEY COLONY NO 2 COND
- KEY COLONY NO 2 CONDOKEY COLONY OCEANSOUN
- KEY COLONY NO 4 CONDO
- KEY COLONY NO 4 CONDO,KEY COLONY NO 4 COND
- KEY COLONY NO 4 CONDOKEY COLONY CONDO #4
- KEY COLONY NO 4 CONDOKEY COLONY NO 4 CO
- KEY ISLANDER CONDO
- Key Islander CondominiumKey Islander Condomi
- LAKE TOWER CONDO
- LAKE TOWER CONDO,Lake Tower
- LAKE TOWER CONDOThe Ocean Club
- LAKE VILLA ONE CONDO,The Ocean Club
- LAKE VILLA THREE CONDO
- LAKE VILLA TWO CONDO
- LAKE VILLA TWO CONDOThe Ocean Club
- LE PHARE KEY BISCAYNE CON
- MAR-AZUL CONDO
- MASHTA ISLAND
- MASHTA ISLAND A REPLAT OF
- MASHTA POINT SUB
- MATHESON ESTATES,MATHESON STATES
- OCEAN LANE PLAZA CONDO
- OCEAN LANE PLAZA CONDO,OCEAN LANE PLAZA CON
- OCEAN TOWER ONE CONDO
- OCEAN TOWER ONE CONDOOCEAN TOWER ONE COND
- OCEAN TOWER TWO CONDO
- OCEAN TOWER TWO CONDO,THE OCEAN CLUB
- OCEAN VILLAGE CONDO
- OCEANA KEY BISCAYNE CONDO
- OCEANA KEY BISCAYNE CONDO,OCEANA KEY BISCAYNE
- OCEANA KEY BISCAYNE CONDOOCEANA KB
- OCEANA KEY BISCAYNE CONDOOCEANA KEY BISCAYNE
- RESORT VILLA ONE CONDO,RESORT VILLA ONE CON
- RESORT VILLA ONE CONDORESORT VILLA ONE
- RESORT VILLA TWO CONDO
- RESORT VILLA TWO CONDOTHE OCEAN CLUB
- SANDS OF KEY BISCAYNE CON
- SANDS OF KEY BISCAYNE CON,SANDS OF KEY BISCAYN
- SMUGGLERS COVE
- SOLIMAR CONDO OF KEY BISC
- SUNRISE CLUB CONDO
- SUNRISE CLUB CONDO,100 SUNRISE
- SUNRISE MANOR CONDO
- THE EMERALD BAY
- THE EMERALDBAY @ KEY COLO
- THE EMERALDBAY @ KEY COLO,KEY COLONY
- THE EMERALDBAY @ KEY COLOKEY COLONY
- THE EMERALDBAY @ KEY COLON,KEY COLONY
- THE EMERALDBAY @ KEY COLOTHE EMERALD BAY
- THE EMERALDBAY @ KEY COLOTHE EMERALDBAY @ KEY
- THE EMERALDBAY @KEY COLONY,THE EMERALDBAY
- THE PALMS OF KEY BISCAYNE
- THE PALMS OF KEY BISCAYNE,The palms of keybis.
- THE PALMS OF KEY BISCAYNEPalms of Key Biscayn
- THE PYRAMIDS @ KEY BISCAY
- TOWERS OF KEY BISCAYNE CO
- TOWERS OF KEY BISCAYNE CO,The Towers of Key Bi
- TOWERS OF KEY BISCAYNE CO,TOWERS OF KEY BISCAY
- TOWERS OF KEY BISCAYNE COTOWERS OF KEY BISCAY
- TROPICAL ISLE HOMES RESUB
- TROPICAL ISLE HOMES SUB
- TROPICAL ISLE HOMES SUB 1
- TROPICAL ISLE HOMES SUB 2N
- TROPICAL ISLE HOMES SUB 3
- TROPICAL ISLE HOMES SUB 4
- TROPICAL ISLE HOMES SUB 4,KEY COLONY
- TROPICAL ISLES HOMESTROPICAL ISLE HOMES
Market Summary
Current real estate data for Single Family in Key Biscayne as of Nov 04, 2026
41
Single Family Listed
162
Avg DOM
2,658
Avg $ / SqFt
$14,656,756
Avg List Price
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 $18,500,000 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 $5,997. The average price per square foot for Single Family listings in Key Biscayne is $2,658. The average listing price for Single Family in Key Biscayne is $14,656,756. To schedule a showing of MLS#a12071221 at 520 S Mashta Dr in Key Biscayne, FL, contact your Julien Drieu agent at 7862380927.
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