MASHTA ISLAND A REPLAT OF
520 S Mashta Dr, Key Biscayne FL 33149
5 beds · 4 baths · 3,085 ft²
$19,900,000
Est. Payment $105,916/mo
5
Bedrooms
4
Bathrooms
3,085
Sq. Ft.
1961
Year Built
2
Garage
7
Days on Market
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.
Facts
- MLS#
- A12071221
- Subdivision
- MASHTA ISLAND A REPLAT OF
- Property Type
- Residential
- Property Sub Type
- Single Family Residence
- Year Built
- 1961
- Lot Size
- 22,140 ft²
- Sq. Ft.
- 3,085 ft²
- Sq. Mt.
- 287 m²
- Price per sq. ft.
- $6,451/ft²
- Price per sq. mt.
- $69,338/m²
- Stories
- —
- Garage
- 2 spaces
- Pool
- —
- Days on Market
- 7 days
- Listed
- Aug 12, 2026
- Last Updated
- Aug 19, 2026
- Price/Lot Sq.Ft.
- $899/ft²
Comparable homes
Same ZIP, similar price + bedrooms.
Market insights for Key Biscayne
Live MLS-derived activity. Forecast is a conservative rule-of-thumb estimate — not a guarantee.
Sellers market
August 2026
50
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).
| 8/12/2026 | Listed for sale | $19,900,000 |
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
$122,649/mo
Principal & Interest
$105,916
Property Tax
$16,583
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 10 hours ago
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