Waterfront
Address
520 S Mashta Dr, Key Biscayne, FL
Price
$ 19,900,000
Property Attributes
- MLS#A12071221
- TypeSingle Family
- Listing Status Active
- CountyMiami-Dade
- CityKey Biscayne
- Area52
- NeighborhoodMASHTA ISLAND A REPLAT OF
- Zip33149
- Style
- Year Built1961
- Taxes$ 201741
- Price$ 19,900,000
- Bedrooms5
- Full Bathrooms4
- Half Bathrooms0
- Sqr Footage3085
Data Source:
Southeast Florida MLS (SEFMLS)
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.
| Elementary School | Middle School | High School |
|---|---|---|
| Keybiscayne Elementary School | Ponce De Leon Middle School | Coral Gables High School |
| Price History | |
|---|---|
| 8/17/2026 | Listed $19,900,000 |
General Features
| Sewer | Public Sewer |
|---|---|
| Heating | Central |
| Cooling | Central Air |
| Possession | Closing & Funding |
| Roof | Barrel,Spanish Tile |
| Appliances | Other |
| Garage Spaces | 2 |
| Architectural Style | One Story |
| Pool Features | In Ground,Pool |
| Restrictions | OK To Lease |
| Construction Materials | Block |
| Year Built | 1961 |
| View | Bay,Ocean |
| Stories Count | 1 |
| Property Subtype | Single Family Residence |
| Tax Year | 2026 |
| Waterfront Features | Bayfront,Ocean Access,Seawall |
| Community Features | Other,See Remarks |
| County | Miami-Dade |
| Property Type | Residential |
| Subdivision Name | MASHTA ISLAND A REPLAT OF |
| Facing Direction | East |
| Garage Y/N | true |
| Full Baths | 4 |
| Special Listing Conditions | Listed As-Is |
| Status | Active |
| High School | Coral Gables |
| City | Key Biscayne |
| Disclosures | None |
| Senior Community Y/N | false |
| Zoning Description | 2001 |
| MLS Area | 52 |
| Lot Size Units | Square Feet |
| Lot Size Square Feet | 22140 |
| Listing Terms | Cash,Conventional |
| Elementary School | Keybiscayne |
| Year Built Details | Resale |
| Tax Annual Amount | 201741 |
| Middle/Junior High School | Ponce De Leon |
| Lease Considered Y/N | false |
| Virtual Tour | https://www.propertypanorama.com/instaview/mia/A12071221 |
| Standard Status | Active |
| Occupancy Type | Call Agent |
| Property Sub Type Additional | Single Family Residence |
| PostalCity | Key Biscayne |
| 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 |
Interior Features
| Interior Amenities | Bedroom on Main Level,First Floor Entry,Split Bedrooms |
|---|---|
| Flooring | Tile |
| Air Conditioning Y/N | true |
| Heating Y/N | true |
| Total Bedrooms | 5 |
| Total Baths | 4 |
Exterior Features
| Exterior Amenities | Security/High Impact Doors |
|---|---|
| Parking Features | Driveway |
| Water Source | Public |
| Lot Size Area | 22140 |
| Building Area Total | 4177 |
| Frontage Length | 138 |
| Private Pool | true |
| Waterfront Y/N | true |
| Covered Spaces | 2 |
Amenities
- Foreclosure
- Views
- Short Sale
- New Construction
- Adult 55+
- Lease To Own
- No HOA Fees
- Furnished
- Primary On Main
- Air Conditioning
- Seller Finance
- Green
- Fixer Upper
- Horse
- Golf
- Fireplace
- Deck
- Garage
- Basement
- Pool
Property vs Single Family Average in 33149
Price
Taxes
Year Built
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Data Last Updated: September 13, 2026 3:47 PM UTC
Information is deemed to be reliable, but is not guaranteed. © 2026 MLS and FBS. Prepared by Florida Keys MLS, Inc. on September 13, 2026 3:47 PM UTC The information on this sheet has been made available by the MLS and may not be the listing of the provider. The data relating to real estate for sale on this web site comes in part from the Florida Keys MLS, Inc. Information provided is deemed reliable but not guaranteed. All properties are subject to prior sale, change or withdrawal. The information
All information deemed reliable but not guaranteed. All properties are subject to prior sale, change or withdrawal. Neither listing broker(s) or information provider(s) shall be responsible for any typographical errors, misinformation, misprints and shall be held totally harmless. Listing(s) information is provided for consumer's personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. The data relating
