$18,500,000
4 bd · 4.5 ba · 2,255 sqft
631 N Mashta Drive, Key Biscayne, FL 33149
640 S Mashta Dr, Key Biscayne, FL 33149
$16,800,0004 Beds4 Baths3,620 Sq. Ft.$4,641 / sq. ft.
Key Biscayne, FL 33149 · MASHTA ISLAND
Status
Active
Type
Single Family Residence
Year Built
1968
Days on Market
170
Lot Size
15,000 sqft
MLS #
A11990382
County
Miami-Dade County
About 640 S Mashta Dr, Key Biscayne, FL 33149
Welcome to your own slice of paradise! Enjoy breathtaking sunsets from your private dock on this waterfront property boasting 100 feet of direct Biscayne Bay frontage. Ideally located on Mashta Island. Set on a 15,000 SF lot, the home features 5 beds, 5 baths, including 2 bayfront primary suites with stunning views, impact windows and doors throughout. The open-concept layout flows seamlessly from the living and dining areas to the modern kitchen and out to the pool and entertainment patio, with floor-to-ceiling glass doors that open to blend indoor and outdoor living. Tranquil guest suite upstairs offering privacy and views. It also features an oversized 2-car garage, covered parking, and a spacious driveway for guests. Perfect to move in, renovate, or build your dream waterfront estate
How This Listing Compares in Key Biscayne
Per square foot, it is asking 379% above the Key Biscayne median for sales closed over the last twelve months — typical of premium views, newer construction or a top-tier building.
| This home | Key Biscayne median (12 mo) | |
|---|---|---|
| Price per sq. ft. | $4,641 | $969 |
| 4-bedroom price | $16,800,000 | $3,450,000 |
| Days on market | 170 | 61 |
Medians from closed MLS sales in Key Biscayne; a starting point, not an appraisal.
Home Features at 640 S Mashta Dr, Key Biscayne, FL 33149
- Bathrooms Full
- 4
- Bathrooms Half
- 0
- Interior Features
- First Floor Entry, Entrance Foyer, Pantry, Split Bedroom, Vaulted Ceiling(s), Walk-In Closet(s), Garage Converted
- Appliances
- Dishwasher
- Flooring
- Other
- Heating
- Other
- Cooling
- Central Air
- Architectural Style
- Attached, Other
- Garage Spaces
- 2
- Attached Garage
- Yes
- Parking Features
- Driveway, Guest
- Pool Features
- In Ground
- Pool Private
- No
- Year Built Details
- Resale
- Direction Faces
- East
The Building at 640 S Mashta Dr, Key Biscayne, FL 33149
- Building Name
- MASHTA ISLAND
- Building Area Total
- 4990
- Building Area Units
- Square Feet
- Association
- No
- Pets Allowed
- Dogs OK
Lot, Views & Construction at 640 S Mashta Dr, Key Biscayne, FL 33149
- Lot Features
- Less Than 1/4 Acre Lot
- Lot Size Square Feet
- 15,000
- Waterfront
- Yes
- Waterfront Features
- Ocean Access, Ocean Front
- Frontage Length
- 100
- View
- Bay, Garden
- Construction Materials
- Concrete Block Construction
- Roof
- Barrel Roof
- Exterior Features
- Other
- Sewer
- Public Sewer
- Water Source
- Municipal Water
- New Construction
- No
Taxes & Public Record for 640 S Mashta Dr, Key Biscayne, FL 33149
- Parcel Number
- 24-52-05-008-0320
- Tax Annual Amount
- $155,651
- Tax Year
- 2,025
- Tax Legal Description
- MASHTA ISLAND PB 60-93 LOT 9 BLK 3 LOT SIZE 100.000 X 150 OR 18642-3922 0599 1
- Zoning
- 2001
- County Or Parish
- Miami-Dade County
Assigned Schools for 640 S Mashta Dr, Key Biscayne, FL 33149
- Elementary School
- Keybiscayne
- Middle School
- Ponce De Leon
- High School
- Coral Gables
School assignments are provided by the listing and should be independently verified.
Map & Neighborhood
640 S Mashta Dr, Key Biscayne, FL 33149 · More homes in Key Biscayne
Courtesy of DLS International Realty
Comparable Listings in Key Biscayne
$16,500,000New
6 bd · 7 ba · 7,103 sqft
131 Cape Florida Dr, Key Biscayne, FL 33149
CAPE FLORIDA SUB SEC 3
$19,900,000
5 bd · 4 ba · 3,085 sqft
520 S Mashta Dr, Key Biscayne, FL 33149
MASHTA ISLAND A REPLAT OF
$14,990,000New
4 bd · 6 ba · 6,661 sqft
161 Cape Florida Drive, Key Biscayne, FL 33149
CAPE FLORIDA SUB SEC 3
$19,950,000
6 bd · 7 ba · 6,208 sqft
120 Knollwood Dr, Key Biscayne, FL 33149
CAPE FLA SUB SEC 2
$12,485,000
6 bd · 8 ba · 6,405 sqft
420 Island Dr, Key Biscayne, FL 33149
CAPE FLORIDA SUB SEC 1
$19,800,000
4 bd · 9 ba · 8,240 sqft
100 Cape Florida Dr, Key Biscayne, FL 33149
CAPE FLORIDA SUB SEC 3
640 S Mashta Dr, Key Biscayne, FL 33149 at a Glance
Offered for sale in Key Biscayne 33149, 640 S Mashta Dr is a single family home with 4 bedrooms, 4 bathrooms, about 3,620 square feet of living space, dating to 1968. The asking price is $16,800,000, on the market since April 2, 2026, with DLS International Realty as the listing brokerage. Students here are assigned to Keybiscayne, Ponce De Leon and Coral Gables. Ask Matthew Gromadzki for a private showing, the full disclosure package, or comparable sales before you make an offer.