MASHTA ISLAND

640 S Mashta Dr, Key Biscayne FL 33149

4 beds · 4 baths · 3,620 ft²

For Sale · Active Listing

$16,800,000

Est. Payment $89,417/mo

MLS Sheet Video

4

Bedrooms

4

Bathrooms

3,620

Sq. Ft.

1968

Year Built

2

Garage

3

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
3 days
Listed
Apr 2, 2026
Last Updated
Apr 5, 2026
Price/Lot Sq.Ft.
$1,120/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

May 2026

100/100
Buyers marketSellers market

77

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).

4/2/2026Listed 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

640 S Mashta Dr, Key Biscayne FL 33149Directions

GreatSchools Summary Ratings

Public + private K-12 schools within 5 miles of this listing.

GreatSchoolsData provided by GreatSchools.org © 2026. All rights reserved.

Estimated Monthly Payment

$103,567/mo

Principal & Interest

$89,417

Property Tax

$14,000

Insurance

$150

HOA

$0

20% ($3,360,000)
7.00%
30 years
1.00% (FL avg ~1.0%)
$0/mo
$150/mo

Estimates only. Actual payment depends on credit, lender, insurance carrier, and FL/Miami-Dade specifics. Contact Rangely for a precise quote.

Rangely Adames

Rangely Adames

Sales Associate | Sunland Group

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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.

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Updated within 24 hours

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