5-Bed Single Family Residence at MASHTA ISLAND A REPLAT OF in Key Biscayne

$19,900,000

Brickellsold Estimate* (fallback: list price)$19,900,000 (list price)
For Sale
bedrooms

5

bathrooms

4

Square Footage

3085

Type of Property

Single Family Residence, Residential

Details

Overview

Sub Type
Single Family Residence
Price Per Sqft
$6,451/sqft
Built In
1961
Taxes
$201,741/yr

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.

This single family residence home located at 520 S Mashta Dr, Key Biscayne FL 33149 is currently for sale and has been available on Brickellsold for 6 days. This property is listed at $20M. It has 5 beds, 4 bathrooms, and is 3085 square feet. It was built in 1961. 520 S Mashta Dr, Key Biscayne FL 33149 is in Key Biscayne county Miami-Dade County.

Interior

Bedrooms
5
Bathrooms
4
Bathrooms Full
4
Features
  • Flooring: Tile
  • Common walls with other units/homes: Attached, One Story
Heating
Central
Cooling
Central Air
Appliances
Other Equipment/Appliances
Total structure area
4,177
Total interior livable area
3,085 sqft

Property

Parking
  • Covered Spaces: 2
  • Parking Features: Driveway
  • Garage Spaces: 2
Parcel Number
24-52-05-009-0170
Features
  • Entry location: First Floor Entry, Split Bedroom, Family Room
  • Exterior Features:
  • Has View: Yes
  • View Description: Bay, Direct Ocean

Construction

Property subtype
Single Family Residence, Residential
Materials
Concrete Block Construction
Condition
  • Year Built: 1961

Community & HOA

Community
  • Security Features:
  • Subdivision: MASHTA ISLAND A REPLAT OF
HOA
  • Amenities:
Region
Key Biscayne

Financial

Price Per Sqft
$6,451/sqft
Taxes
$201,741/yr
On Market Date
8/11/2026
Listing Terms
All Cash, Conventional

Metadata

Added
8/17/2026
Updated
8/18/2026
MLS#
A12071221
Days on Market
6
Listed By
Coldwell Banker Realty
Originating MLS
A-Miami Association of REALTORS

Map

Price History

EventPriceDate
Original list price$19,900,000Aug 17, 2026

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