1 / 38
See all 38
520 S Mashta Dr, Key Biscayne, FL 33149
Reduced $1,400,000 on Oct 23, 2026
5 bd · 4 ba · 3,085 sqft · 0.51 acres (22,140 sqft) · 84 days on market · MLS# A12071221
Request Property Documents For 520 S Mashta Dr, Key Biscayne, FL 33149
Request a document for this home and we'll follow up with it.
Seller's Disclosure
Property Survey
Floor Plan
Comparative Market Analysis
About 520 S Mashta Dr, Key Biscayne, FL 33149
Listing details for 520 S Mashta Dr, Key Biscayne, FL 33149: 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.
Bedrooms
5
Bathrooms
4
Square Feet
3,085
Year Built
1961
Lot
0.51 acres (22,140 sqft)
Garage
2 spaces
HOA
No
Taxes (2026)
$201,741
Property Details for 520 S Mashta Dr, Key Biscayne, FL 33149
MLS# A12071221 · Source: MIAMI + RWorld · Updated Nov 4, 2026
Interior
Bedrooms & Bathrooms
- Bedrooms: 5
- Full Baths: 4
- Half Baths: 0
Heating & Cooling
- Heating: Central
- Cooling: Central Air
Interior Features
- Interior Features: Bedroom on Main Level, First Floor Entry, Split Bedrooms
- Flooring: Tile
- Has Fireplace: No
Interior Area
- Total Interior Livable Area: 3,085 sqft
- Total Structure Area: 4,177 sqft
Property
Parking
- Has Garage
- Yes
- Garage Spaces
- 2
- Covered Spaces
- 2
- Parking Features
- Driveway
Features
- Stories
- 1
- Direction Faces
- East
- Exterior Features
- Security High Impact Doors
- Has Private Pool
- Yes
- Pool Features
- In-Ground, Pool
- View Description
- Bay, Ocean
- Waterfront
- Yes
- Waterfront Features
- Bayfront, Ocean Access, Seawall
Lot
- Lot Size
- 0.51 acres (22,140 sqft)
- Lot Features
- Flood Zone
Details
- Parcel Number
- 24-52-05-009-0170
- Zoning
- 2001
- 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
Construction
Type & Style
- Home Type
- Single Family Residence
- Property Type
- Residential
- Architectural Style
- One Story
Materials
- Construction Materials
- Block
- Roof
- Barrel, Spanish Tile
Condition
- Condition
- Resale
- New Construction
- No
- Year Built
- 1961
Utilities & Green Energy
- Water Source
- Public
- Sewer
- Public Sewer
Community & HOA
Community
- Subdivision
- Mashta Island A Replat of
- Community Features
- See Remarks
- Restrictions
- OK to Lease
- 55+ Community
- No
Housing in Village Of Key Biscayne
- Median Value of All Homes (2023 Census)
- $1,246,268
- Median Rent
- $3,394/mo
- Owner-Occupied Homes
- 69%
- Homes Built
- Mostly 1970s
- Housing Units
- 4,994
HOA
- Membership Required
- No
Location
- Neighborhood
- Village Of Key Biscayne
Financial & Listing Details
- Price per Sq Ft
- $5,997/sq ft
- Annual Tax Amount
- $201,741
- Tax Year
- 2026
- Date on Market
- Aug 12, 2026
- Cumulative Days on Market
- 84 days
- Listing Terms
- Cash, Conventional
- Special Conditions
- Listed As Is
- Possession
- Closing and Funding
- Occupant Type
- Call Agent
- MLS Number
- A12071221
- Listed By
- Maureen Jauregui — Coldwell Banker Realty, Emma Jauregui — Coldwell Banker Realty
Mashta Island A Replat of
Mashta Island A Replat of is a neighborhood in Key Biscayne. Census median home value is $1,246,268.
Location of 520 S Mashta Dr, Key Biscayne, FL 33149
- Street Address
- 520 S Mashta Dr
- City
- Key Biscayne
- ZIP Code
- 33149
- Neighborhood
- Mashta Island A Replat of
- County
- Miami-Dade County
Estimated monthly
30-yr fixed
$121,668
/mo
$18,500,000 · 20% down · 7.25%
Principal & interest
$101,002
Property taxes
$16,812
Home insurance
$3,854
Home price
$18,500,000
Down payment
$3,700,000 · 20%
Interest rate
7.25%
Estimates only. Actual costs vary by lender, credit score, and market conditions.
Frequently Asked Questions About 520 S Mashta Dr
How much is 520 S Mashta Dr, Key Biscayne, FL 33149 listed for?
520 S Mashta Dr, Key Biscayne, FL 33149 is currently listed at $18,500,000. That works out to approximately $5,997 per square foot.
How big is 520 S Mashta Dr?
This property features 5 bedrooms, 4 bathrooms, 3,085 sq ft of living space.
What are the property taxes on 520 S Mashta Dr, Key Biscayne, FL 33149?
The most recent tax bill for 520 S Mashta Dr, Key Biscayne, FL 33149 is $201,741/yr (~$16,812/mo). Florida primary residents may qualify for a homestead exemption that reduces this amount.
Are there HOA fees at 520 S Mashta Dr?
Based on current MLS data, no HOA fee is listed for this property. We recommend confirming with the seller's disclosure or your agent, as some communities charge fees not reflected in MLS.
Which schools are zoned for 520 S Mashta Dr, Key Biscayne, FL 33149?
Based on attendance-zone data, this home is zoned for: Key Biscayne K-8 Center (Elementary), Ponce De Leon Middle School (Middle), Coral Gables Senior High School (High). School assignments are set by the county board and may change. Verify current boundaries with Miami-Dade County Public Schools before enrolling.
How does the list price compare to Mashta Island A Replat of home values?
At $18,500,000, this home is listed 1384% above the Mashta Island A Replat of census median home value of $1,246,268. Actual sale price is set by negotiation.
Related Pages for Key Biscayne, FL
Explore more information about the area, neighborhood, and property types
Browse South Florida Cities
Browse South Florida Cities & Clubs
Explore Nearby Cities
Browse homes for sale in cities near Key Biscayne
Explore Cities & Clubs
Browse South Florida cities and private club communities
Listing Information & Disclaimer
Listed By: Coldwell Banker Realty · 305.798.3124
All listings featuring the BMLS logo are provided by BeachesMLS, Inc. This information is not verified for authenticity or accuracy and is not guaranteed. Copyright ©2026 BeachesMLS, Inc.
Listing information is provided in part by the MIAMI + RWorld Internet Data Exchange program. IDX information is provided exclusively for consumers' personal, non-commercial use, and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Data is deemed reliable but is not guaranteed accurate by the MLS. Data last updated Nov 15, 2026 4:58 PM. Equal Housing Opportunity.
To report inaccurate listing data, email andy@mandelteam.com or call (954) 610-0563. Inaccurate information is corrected within two business days, and within 48 hours for registered users.