
MIAMI REALTORS® MLS↓ Price reduced $1,400,000 on Oct 23, 2026
520 S Mashta Drive, Key Biscayne, FL 33149
- Beds
- 5
- Baths
- 4
- Sqft
- 3,085
- Home type
- Single Family Residence
- Year built
- 1961
- Lot size
- 22,216 sqft
- Price / sqft
- $5,997
- HOA
- $0/mo
- Community
- MASHTA ISLAND A REPLAT OF
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.
Listing activity
- Days on market
- 78
- Listed
- Aug 12, 2026
- MLS listing updated
- Oct 29, 2026
- Feed last checked
- 6 minutes ago
Listed by Maureen Jauregui · Coldwell Banker Realty
Map
Map location is based on MLS-supplied coordinates. Verify the location before relying on it.
Facts & features
Interior
Bedrooms & bathrooms
- Bedrooms
- 5
- Bathrooms
- 4
- Bathrooms (decimal)
- 4
- Full bathrooms
- 4
- Half bathrooms
- 0
Rooms & features
- Rooms
- 1
- Interior features
- Bedroom Layout - Split
- Flooring
- Tile
- Appliances
- Other
- Other equipment
- Other
Heating & cooling
- Heating
- Central
- Cooling
- Central Air
Property
Parking
- Garage spaces
- 2
- Garage
- Yes
- Covered spaces
- 2
- Parking features
- Driveway
- Attached garage
- No
Exterior
- Stories
- 1
- Building area
- 4,177 sqft
- Entry level
- 1
- Pool
- Yes
- Pool features
- In Ground
- View
- Direct Ocean, Bay
- Waterfront
- Ocean Access, Bay, Seawall
- Waterfront property
- Yes
Lot
- Lot size
- 22,216 sqft
- Lot size (acres)
- 0.51 acres
- Zoning
- 2001
Construction
Type & style
- Home type
- Single Family Residence
- Year built
- 1961
- New construction
- No
Materials
- Construction
- Block
- Roof
- Barrel, Spanish Tile
- Property condition
- Resale
- Levels
- One
- Faces
- East
Utilities & green energy
Utilities
- Sewer
- Public Sewer
- Water
- Public
Community & HOA
Community
- Subdivision
- MASHTA ISLAND A REPLAT OF
- MLS area
- 2520
- 55+ community
- No
Association
- Has association
- No
- Estimated monthly dues
- $0
- Amenities
- Other
Lease details
Not reported by the listing source.
Location
Area details
- City
- Key Biscayne
- County
- Miami-Dade
- ZIP code
- 33149
Manufactured home details
Not reported by the listing source.
Financial & listing details
Listing
- MLS number
- A12071221
- Possession
- Negotiable
- Original list price
- $19,900,000
- Parcel number
- 2452050090170
- Annual property tax
- $201,741
- 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
Additional MLS details
Reported by the listing source
- Association Amenities
- Other
- Association
- No
- Bathrooms Total Decimal
- 4
- Bathrooms Total Integer
- 4
- Building Area Total
- 4177
- Construction Materials
- Block
- County Or Parish
- Miami-Dade
- Days On Market
- 78
- Direction Faces
- East
- Elementary School
- Key Biscayne K-8
- High School
- Coral Gables
- List Price
- 18500000
- Listing Contract Date
- 2026-08-12
- Living Area
- 3085
- Lot Size Acres
- 0.51
- Lot Size Area
- 22140
- MLSArea Major
- 2520
- Middle Or Junior School
- Ponce De Leon
- Mls Status
- Active
- On Market Date
- 2026-08-12
- Photos Count
- 38
- Postal Code
- 33149
- Price Change Timestamp
- 2026-10-23T18:08:11Z
- Property Sub Type
- Single Family Residence
- Property Type
- Residential
- Rooms Total
- 1
- Senior Community
- No
- Standard Status
- Active
- State Or Province
- FL
- Status Change Timestamp
- 2026-08-12T04:00:00Z
- Stories Total
- 1
- Subdivision Name
- MASHTA ISLAND A REPLAT OF
- Water Source
- Public
- Waterfront Features
- Ocean Access, Bay, Seawall
- Tax Annual Amount
- 201741
- Bathrooms Full
- 4
- Pool Private
- Yes
- Bedrooms Total
- 5
- Bathrooms Half
- 0
Market value
Price history
| Date | Event | Price |
|---|---|---|
| Aug 12, 2026 | ListedMIAMI REALTORS® MLS | $19,900,000$6,451/sqft |
| Oct 23, 2026 | Price reducedMIAMI REALTORS® MLS | $18,500,000$5,997/sqft |
Public tax history
| Year | Property taxes | Assessment |
|---|---|---|
| 2026 | $201,741 | — |
Payment calculator
- Principal & interest
- $95,993
- Property taxes
- $16,812
- Insurance
- $9,250
- Association dues
- $0
Live national rate context is displayed below through Mortgage News Daily’s official widget. The calculator rate remains a separate assumption until licensed machine-readable access is connected. This is not a loan offer.
Neighborhood
Area
MASHTA ISLAND A REPLAT OFKey Biscayne · Miami-Dade County · 33149
Climate risk
—No licensed climate-risk source is connected.
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