MASHTA ISLAND
640 S Mashta Dr, Key Biscayne FL 33149
4 beds · 4 baths · 3,620 ft²
$16,800,000
Est. Payment $89,417/mo
4
Bedrooms
4
Bathrooms
3,620
Sq. Ft.
1968
Year Built
2
Garage
65
Days on Market
Description
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
Facts
- MLS#
- A11990382
- Subdivision
- MASHTA ISLAND
- Property Type
- Residential
- Property Sub Type
- Single Family Residence
- Year Built
- 1968
- Lot Size
- 15,000 ft²
- Sq. Ft.
- 3,620 ft²
- Sq. Mt.
- 336 m²
- Price per sq. ft.
- $4,641/ft²
- Price per sq. mt.
- $50,000/m²
- Stories
- —
- Garage
- 2 spaces
- Pool
- —
- Days on Market
- 65 days
- Listed
- Apr 2, 2026
- Last Updated
- Apr 5, 2026
- Price/Lot Sq.Ft.
- $1,120/ft²
Comparable homes
Same ZIP, similar price + bedrooms.
SOLD$17,200,000
4 bd · 4 ba · 3,085 sqft
520 S MASHTA DR, Key Biscayne FL 33149
SOLD$15,500,000
4 bd · 5 ba · 4,290 sqft
591 N Mashta Dr, Key Biscayne FL 33149
SOLD$14,900,000
5 bd · 6 ba · 7,004 sqft
260 Harbor Dr, Key Biscayne FL 33149
$19,900,000
5 bd · 4 ba · 3,085 sqft
520 S Mashta Dr, Key Biscayne FL 33149
SOLD$13,870,000
5 bd · 6 ba · 8,435 sqft
445 Grand Bay Dr # 1A, Key Biscayne FL 33149
Market insights for Key Biscayne
Live MLS-derived activity. Forecast is a conservative rule-of-thumb estimate — not a guarantee.
Sellers market
August 2026
49
Median days to sold
+4.5%
1-year price forecast (est.)
Price & tax history
From the live MIAMI MLS feed. Older history requires the ListingHistory resource (not yet enabled).
| 4/2/2026 | Listed for sale | $16,800,000 |
History reflects fields present on the live MLS record. Full multi-year history requires the MIAMI ListingHistory resource (not yet enabled).
Location
Estimated Monthly Payment
$103,567/mo
Principal & Interest
$89,417
Property Tax
$14,000
Insurance
$150
HOA
$0
Estimates only. Actual payment depends on credit, lender, insurance carrier, and FL/Miami-Dade specifics. Contact Rangely for a precise quote.
The data relating to real estate for sale on this website comes in part from the Southeast Florida Multiple Listing Service. MLS Data is deemed reliable, but is not guaranteed accurate by MIAMI REALTORS®.
Accuracy of listing information is not guaranteed. Listing information is provided for personal consumer, non-commercial use, solely to identify potential properties for potential purchase. All other use is strictly prohibited and may be a violation of federal and state law.
Copyright Southeast Florida MLS a/k/a SEFMLS © 2026.
Updated within 24 hours
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