How much is 640 S Mashta Drive?

640 S Mashta Drive is listed at $16,800,000, which is about $4,641 per square foot. The listing page shows comparable active listings and recent closed sales nearby so you can judge the asking price against what buyers have actually paid.

What are the property taxes on 640 S Mashta Drive?

The listing reports annual property taxes of $155,651 for 2025. Taxes are reassessed at the sale price after a purchase, so a new owner's bill can differ from the current owner's; use the mortgage calculator on this page for an estimate.

When was 640 S Mashta Drive built?

640 S Mashta Drive was built in 1968 and the listing describes its condition as resale. Age matters for insurance and financing in Florida: ask about the roof, the electrical panel and, for a condo built before the current code, the building's structural reserve study.

How long has 640 S Mashta Drive been on the market?

640 S Mashta Drive has been listed for 220 days. Days on market and price changes are the first signals of how much room there is to negotiate.

Is 640 S Mashta Drive waterfront?

Yes. The listing describes the water as ocean front. For a home with dockage, confirm the water depth at low tide, the seawall condition and whether the route to the inlet passes under any fixed bridges before you offer.

Which schools serve 640 S Mashta Drive?

The MLS lists Key Biscayne K-8 (elementary), Ponce De Leon (middle), Coral Gables (high). School assignments are set by the district and can change; verify them with the school board before you rely on them.

How do I see 640 S Mashta Drive?

Request a showing from this page or call BreakThru Realty and a licensed agent will arrange a private tour, in person or by video, and answer anything the listing leaves out.

640 S Mashta Drive, Key Biscayne, FL 33149

$16,800,000 · Active

4 beds
4 baths
3,620 sq ft
220 days on market
Single Family Residence
Built 1968
Lot 14,810.4 sq ft
4,990 sq ft total
2 garage spaces
Miami-Dade County
MLS# A11990382
Mashta Island

Photo 1 at 640 S Mashta Drive, Key Biscayne

Photo 2 at 640 S Mashta Drive, Key Biscayne

Photo 3 at 640 S Mashta Drive, Key Biscayne

Photo 4 at 640 S Mashta Drive, Key Biscayne

Photo 5 at 640 S Mashta Drive, Key Biscayne

Photo 6 at 640 S Mashta Drive, Key Biscayne

Photo 7 at 640 S Mashta Drive, Key Biscayne

Photo 8 at 640 S Mashta Drive, Key Biscayne

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

Features

Entrance Foyer
Pantry
Vaulted Ceiling(s)
Walk-In Closet(s)
Bedroom Layout - Split
Other
Ocean Front
In Ground

Schools

Elementary: Key Biscayne K-8
Middle: Ponce De Leon
High: Coral Gables

Presented by

BreakThru Realty · (786) 914-1017

Courtesy of

DLS International Realty · dls.realtykb@gmail.com · Listing agent: Brigitte De Langeron

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. 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 BeachesMLS. Listings held by brokerage firms other than BreakThru Realty carry the name of the listing broker.

Schedule a showing

Call or text BreakThru Realty at (786) 914-1017 or email sales@breakthrurealty.com to see 640 S Mashta Drive.

Before You Make an Offer

Buying a beachfront home in Florida

How buying a home in South Florida works

Your Waterfront Buyer May Already Be Working With Us

BreakThru Realty works with buyers searching for waterfront homes with ocean access, no fixed bridges, deep water, private docks and Intracoastal frontage. Boaters know the vessel they need to keep behind the house, and they tell us. If you own a waterfront home, a broker can compare its frontage, dock and route to the ocean with those requirements and discuss a potential buyer match before you list.

BreakThru Realty works with hundreds of prequalified buyers searching for properties. Before you list, a broker reviews what you own, the market around it and whether an existing buyer's requirements match. If none does, you see how we would position it to reach other qualified buyers.

Find Out If We Have Your Buyer · Discuss Selling With BreakThru Realty

A potential match is a conversation, not an offer, until the buyer sees your property and makes one. No buyer is named and nothing about your property or business is shared until you decide to proceed.

Questions About 640 S Mashta Drive

How much is 640 S Mashta Drive?: 640 S Mashta Drive is listed at $16,800,000, which is about $4,641 per square foot. The listing page shows comparable active listings and recent closed sales nearby so you can judge the asking price against what buyers have actually paid.
What are the property taxes on 640 S Mashta Drive?: The listing reports annual property taxes of $155,651 for 2025. Taxes are reassessed at the sale price after a purchase, so a new owner's bill can differ from the current owner's; use the mortgage calculator on this page for an estimate.
When was 640 S Mashta Drive built?: 640 S Mashta Drive was built in 1968 and the listing describes its condition as resale. Age matters for insurance and financing in Florida: ask about the roof, the electrical panel and, for a condo built before the current code, the building's structural reserve study.
How long has 640 S Mashta Drive been on the market?: 640 S Mashta Drive has been listed for 220 days. Days on market and price changes are the first signals of how much room there is to negotiate.
Is 640 S Mashta Drive waterfront?: Yes. The listing describes the water as ocean front. For a home with dockage, confirm the water depth at low tide, the seawall condition and whether the route to the inlet passes under any fixed bridges before you offer.
Which schools serve 640 S Mashta Drive?: The MLS lists Key Biscayne K-8 (elementary), Ponce De Leon (middle), Coral Gables (high). School assignments are set by the district and can change; verify them with the school board before you rely on them.
How do I see 640 S Mashta Drive?: Request a showing from this page or call BreakThru Realty and a licensed agent will arrange a private tour, in person or by video, and answer anything the listing leaves out.
To request a tour, call (786) 914-1017 or email sales@breakthrurealty.com.

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The 4 bedroom home at 631 N Mashta Drive, Key Biscayne, FL 33149 is comparable and listed for sale at $18,500,000. Another comparable home, 591 N Mashta Drive, Key Biscayne, FL 33149, sold for $14,000,000 in August 2026. Key Biscayne neighborhoods include Biscayne Key Estates and Tropical Isle Homes. Nearby ZIP codes include 33133 and 33131. This property also neighbors Coconut Grove, Brickell, and Miami. Compare it with the Key Biscayne housing market report.