$19,900,000
Key Biscayne, FL 33149
MLS# A12071221
5 beds | 4 baths | 4177 sqft
1 / 38
Property Description
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.
Details
Maps
Contract Information
Comp Sale YN: No
Occupant Type: Call Listing Agent
Listing Date: 2026-08-12
Status: Active
Original List Price: 19900000
List Price: $19,900,000
Current Price: $19,900,000
Location and Legal
County Or Parish: Miami-Dade
County Parish Name: Miami-Dade
City Name: Key Biscayne
Municipal Code: 24
Postal Zip: 33149
Subdivision Number: 9
Flood Zone: AE
Country: United States
Street Number: 520
Street Direction Prefix: S
Street Name: Mashta
Street Suffix: Drive
State Or Province: FL
Postal Code: 33149
Postal Code +4: 1733
Subdivision Name: MASHTA ISLAND A REPLAT OF
Area: 2520
Elementary School: Key Biscayne K-8
Middle Or Junior School: Ponce De Leon
High School: Coral Gables
Parcel Number: 2452050090170
Zoning: 2001
General Property Information
Adjusted Area Main: 3578
Living Area Main: 3085
Lot Size Area: 22140
Water Frontage Feet: 138
Senior Community YN: No
Stories Total: 1
Pool Private YN: Yes
Property Sub Type: Single Family Residence
Bedrooms Total: 5
Bathrooms Total: 4
Bathrooms Full: 4
Building Area Main: 4177
Year Built: 1961
Garage YN: 1
Garage Spaces: 2
Covered Spaces: 2
Lot Size Acres: 0.51
Waterfront YN: 1
Direction Faces: East
Financial Information
Estimated Monthly Assoc Recurring Fee: 0
Membership Fee Required YN: No
Tax Annual Amount: 201741
Tax Year: 2026
Tax Legal Description: 5-6 55 42 MASHTA ISLAND A REPLAT OF TRS A & C SELY35FT LOT 16 & ALL LT 17 BLK BLK 3 LOT SIZE 135.000 X 164 OR 15816-1278 1292 1
Office/Member Information
DXORIGMLSID: SEF
Amenities
Other: 1
Entry Information
Entry Level: 1
Flooring
Tile: 1
Leasing Permitted Details
Leasing Permitted YN: Yes
Okay To Lease: 1
Parking Features
Driveway: 1
Property Condition
Resale: 1
Possession
Negotiable: 1
Sewer
Public Sewer: 1
Special Information
Sold As-Is: 1
Heating
Central: 1
Water Access
Ocean Access: 1
Water View
Bay: 1
Direct Ocean: 1
Appliances
Other: 1
Construction Materials
Block: 1
Interior Features
Bedroom Layout - Split: 1
Levels
One: 1
Listing Terms
Cash: 1
Conventional: 1
Other Equipment
Other: 1
Pool Features
In Ground: 1
Roof
Barrel: 1
Spanish Tile: 1
Water Source
Public: 1
Waterfront Features
Bayfront: 1
Seawall: 1
Boat and Dock Information
Dock: Yes
Boat and Dock Features
Private Dock: 1
Cooling
Central Air: 1
Showing Requirements
Call Listing Agent: 1
Master Bedroom/Bath
Master Bdrm - Ground: 1
Pool Size Details
Pool Size (WxL): 0
Storm Protection
Impact Glass: Partial
Room Types
Family Room: 1
Price Calculations
Current Price To SqFt: 6450.56
Section Details
Parcel Number MLX: 0170
Acreage Description
1/2 To Less Than 1 Acre Lot: 1
Status Change Information
Major Change Timestamp: 2026-08-12T04:00:00Z
Major Change Type: New Listing
Status Change Date: 2026-08-17
Originating Details
Originating System Key: 550489621
Originating System ID: M00000151
Property Features
Flooring: Tile
Leasing Permitted Details: Okay To Lease
Parking Features: Driveway
Property Condition: Resale
Appliances: Other
Boat and Dock Features: Private Dock
Construction Materials: Block
Cooling: Central Air
Heating: Central
Interior Features: Bedroom Layout - Split
Levels: One
Listing Terms: Cash; Conventional
Other Equipment: Other
Pool Features: In Ground
Possession: Negotiable
Roof: Barrel; Spanish Tile
Sewer: Public Sewer
Special Information: Sold As-Is
Water Access: Ocean Access
Water Source: Public
Water View: Bay; Direct Ocean
Waterfront Features: Bayfront; Seawall
Showing Requirements: Call Listing Agent
Room Types: Family Room
Acreage Description: 1/2 To Less Than 1 Acre Lot
Room Information
| Room Name |
| Family Room |
Listing Office: Coldwell Banker Realty
Last Updated: August - 26 - 2026
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