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:
$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
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
- 544-548 FERNWOOD CONDO
- BAHAMA HOUSE CONDO,Bahama House
- BAHAMA HOUSE SOUTH CONDO
- BAHIA MAR CONDO OF KEY BI
- BISCAYNE KEY ESTATES
- BLUE PELICAN CONDO
- CAPE FLA CLUB CONDO CLUST
- CAPE FLA SUB SEC 2
- CAPE FLORIDA CLIB CONDO P
- CAPE FLORIDA CLUB CONDO P
- CAPE FLORIDA CLUB CONDO P,CAPE FLORIDA CLUB
- CAPE FLORIDA SUB SEC 1
- CAPE FLORIDA SUB SEC 1,CAPE FLORIDA SUB
- CAPE FLORIDA SUB SEC 3
- CAPE FLORIDA SUB SEC 3,Village Estate
- CASA DEL MAR
- CASA DEL MAR CONDO
- CASA DEL MAR CONDO,CASA DEL MAR
- CAY POLYNESIA CONDO
- CLUB TOWER ONE CONDO
- CLUB TOWER ONE CONDO,Ocean Club
- CLUB TOWER ONE CONDO,THE OCEAN CLUB
- CLUB TOWER THREE CONDO
- CLUB TOWER TWO CONDO
- CLUB TOWER TWO CONDO,Ocean Club
- CLUB TOWER TWO CONDO,THE OCEAN CLUB
- COMMODORE CLUB SOUTH COND
- COMMODORE CLUB SOUTH COND,COMMODORE CLUB SOUTH
- COMMODORE CLUB WEST CONDO
- Crandon Tower Condo
- Fernwood Homes Condo
- G B VILLAS
- GALEN BREAKERS CONDO
- GALEN BREAKERS CONDOMINIU
- GALEN BREAKERS CONDOMINIU,GALEN BREAKERS CONDO
- Galen Drive Condo Apt
- GALEN DRIVE CONDO APTS
- GRAND BAY RESIDENCES COND
- GRAND BAY RESIDENCES COND,GRAND BAY
- GRAND BAY RESIDENCES COND,Grand Bay Residences
- GRAND BAY TOWER CONDO
- GRAND BAY TOWER CONDO,GRAND BAY TOWER COND
- GRAPETREE TOWNHOUSE CONDO
- HOLIDAY COLONY
- HURRICANE COVE
- INDIES CONDO
- ISLAND HOUSE
- ISLAND HOUSE APT INC – CO
- ISLAND HOUSE APT INC – CO,Island House Apt Inc
- KEY BISC AMBASSADOR CONDO
- KEY BISC AMBASSADOR CONDO,KEY BISC AMBASSADOR
- Key Biscayne Ambassador,KB Ambassador
- KEY BISCAYNE COMMODORE CL
- KEY BISCAYNE COMMODORE CL,COMMODORE CLUB ONE
- KEY BISCAYNE COMMODORE CL,Commodore East
- KEY BISCAYNE COMMODORE CL,KEY BISCAYNE COMMODO
- KEY BISCAYNE ONE HUNDRED
- KEY BISCAYNE VI CONDO
- KEY BISCAYNES COMMODORE C
- KEY BISCAYNES COMMODORE C,KEY BISCAYNES COMMOD
- KEY CASSA CONDOMINIUMS
- KEY COLONY CONDO #4
- KEY COLONY CONDO #4,KEY COLONY CONDO 4
- KEY COLONY NO 1
- KEY COLONY NO 1,KEY COLONOY 1
- KEY COLONY NO 1,Key Colony
- KEY COLONY NO 2 CONDO
- KEY COLONY NO 2 CONDO,KEY COLONY NO 2
- KEY COLONY NO 2 CONDO,KEY COLONY NO 2 COND
- KEY COLONY NO 4 CONDO
- KEY COLONY NO 4 CONDO,BOTANICA/FERNERY
- KEY COLONY NO 4 CONDO,KEY COLONY NO 4 COND
- KEY COLONY TIDEMARK
- KEY ISLANDER CONDO
- KEY ISLANDER CONDO,Key Islander Condo
- Key Islander Condominium,Key Islander Condomi
- KEY TOWNHOUSE CONDO
- LAKE TOWER CONDO
- LAKE TOWER CONDO,Lake Tower
- LAKE VILLA ONE CONDO,The Ocean Club
- LAKE VILLA THREE CONDO
- LAKE VILLA THREE CONDO,LAKE VILLA THREE CON
- LAKE VILLA TWO CONDO
- Le Phare Condo,Le phare
- LE PHARE KEY BISCAYNE CON
- Mar Azul,Mar Azul Condo
- MAR-AZUL CONDO
- MASHTA ISLAND
- MASHTA ISLAND A REPLAT OF
- MATHESON ESTATES
- MATHESON ESTATES,MATHESON STATES
- OCEAN DRIVE MANORS INC CO,OCEAN DRIVE MANORS I
- OCEAN LANE PLAZA CONDO
- OCEAN TOWER ONE CONDO
- OCEAN TOWER TWO CONDO
- OCEAN TOWER TWO CONDO,Ocean Club
- OCEAN TOWER TWO CONDO,THE OCEAN CLUB
- OCEAN VILLAGE CONDO
- OCEAN VILLAGE CONDO,OCEAN VILLAGE
- OCEAN VILLAGE CONDO,Ocean Village Condo
- OCEANA KEY BISCAYNE CONDO
- OCEANA KEY BISCAYNE CONDO,OCEANA
- OCEANA KEY BISCAYNE CONDO,OCEANA KEY BISCAYNE
- RESORT VILLA ONE CONDO
- RESORT VILLA ONE CONDO,RESORT VILLA ONE CON
- RESORT VILLA TWO CONDO
- RESORT VILLA TWO CONDO,RESORT VILLA TWO CON
- RESORT VILLA TWO CONDO,The Ocean Club
- SANDS OF KEY BISCAYNE CON
- 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 COLO,THE EMERALD BAY
- THE EMERALDBAY @ KEY COLO,THE EMERALDBAY @ KEY
- THE EMERALDBAY @ KEY COLON
- THE EMERALDBAY KEY COLONY
- The Ocean Club
- THE PALMS OF KEY BISCAYNE
- THE PYRAMIDS @ KEY BISCAY
- TIDEMARK KEY COLONY NO 1,Key Colony
- 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 CON
- TROPICAL ISLE HOMES SUB
- TROPICAL ISLE HOMES SUB 1
- TROPICAL ISLE HOMES SUB 1,TROPICAL ISLE HOMES
- TROPICAL ISLE HOMES SUB 2
- TROPICAL ISLE HOMES SUB 2N
- TROPICAL ISLE HOMES SUB 3
- TROPICAL ISLE HOMES SUB 3,TROPICAL ISLE HOMES
- TROPICAL ISLE HOMES SUB 4
- TROPICAL ISLE HOMES SUB 4,TROPIAL ISLE HOMES
- VILLAHARBOUR APTS CONDO
Market Summary
Current real estate data for Single Family in Key Biscayne as of Sep 18, 2026
45
Single Family Listed
164
Avg DOM
2,762
Avg $ / SqFt
$14,183,356
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 $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 $2,762. The average listing price for Single Family in Key Biscayne is $14,183,356. To schedule a showing of MLS#a12071221 at 520 S Mashta Dr in Key Biscayne, FL, contact your Julien Drieu agent at 7862380927.
Similar Listings Nearby
520 S Mashta Dr
Key Biscayne, FL