640 S Mashta, Key Biscayne, FL 33149

Local realty services provided by:CENTURY 21 Move With Us
640 S Mashta,Key Biscayne, FL 33149
$16,800,000
  • 4 Beds
  • 4 Baths
  • 3,620 sq. ft.
  • Single family
  • Active
Listed by: brigitte de langeron
Office: dls international realty
MLS#:A11990382
Source:FL_RAMC

Price summary

  • Price:$16,800,000
  • Price per sq. ft.:$3,366.73

About this home

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

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Home facts

  • Year built:1968
  • Subdivision & Development:MASHTA ISLAND
  • Listing ID #:A11990382
  • Added:12 day(s) ago
  • Updated:September 13, 2026 at 03:01 PM

Rooms and interior

  • Bedrooms:4
  • Total bathrooms:4
  • Full bathrooms:4
  • Dining Description:Breakfast Area, Living/Dining Room
  • Bathrooms Description:Dual Sinks
  • Kitchen Description:Dishwasher, Pantry
  • Bedroom Description:Split Bedroom, Walk-In Closet(s)
  • Living area:3,620 sq. ft.

Heating and cooling

  • Cooling:Central Air
  • Central air:Yes

Structure and exterior

  • Roof:Barrel Tile
  • Year built:1968
  • Building area:3,620 sq. ft.
  • Construction Materials:Block, Concrete

Utilities

  • Water:Public Water, Water Available, Water Connected
  • Sewer:Public Sewer, Sewer Available

Finances and disclosures

  • Price:$16,800,000
  • Price per sq. ft.:$3,366.73
  • Tax amount:$155,651 (2025)

Features and amenities

  • Appliances:Dishwasher
  • Amenities:Cathedral Ceilings, Entrance Foyer, Pantry
  • Pool features:In Ground

Parking

  • Total parking spaces:2
  • Parking description:Attached, Driveway, Garage, Garage Door Opener, Guest
  • Garage:Yes
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