How much is 520 S Mashta Drive?

520 S Mashta Drive is listed at $19,900,000, which is about $6,451 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 520 S Mashta Drive?

The listing reports annual property taxes of $201,741 for 2026. 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 520 S Mashta Drive built?

520 S Mashta Drive was built in 1961 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 520 S Mashta Drive been on the market?

520 S Mashta Drive has been listed for 42 days. Days on market and price changes are the first signals of how much room there is to negotiate.

Is 520 S Mashta Drive waterfront?

Yes. The listing describes the water as ocean access seawall bayfront. 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 520 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 520 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.

520 S Mashta Drive, Key Biscayne, FL 33149

$19,900,000 · Active

5 beds
4 baths
3,085 sq ft
Single Family Residence
Built 1961
Lot 22,215.6 sq ft
MLS# A12071221
Mashta Island A Replat Of

Photo 1 at 520 S Mashta Drive, Key Biscayne

Photo 2 at 520 S Mashta Drive, Key Biscayne

Photo 3 at 520 S Mashta Drive, Key Biscayne

Photo 4 at 520 S Mashta Drive, Key Biscayne

Photo 5 at 520 S Mashta Drive, Key Biscayne

Photo 6 at 520 S Mashta Drive, Key Biscayne

Photo 7 at 520 S Mashta Drive, Key Biscayne

Photo 8 at 520 S Mashta Drive, Key Biscayne

About this home

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.

Features

Bedroom Layout - Split
Ocean Access
Seawall
Bayfront
In Ground

Schools

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

Presented by

BreakThru Realty · (786) 914-1017

Courtesy of

Coldwell Banker Realty · Listing agent: Maureen Jauregui

Schedule a showing

Call or text BreakThru Realty at (786) 914-1017 or email sales@breakthrurealty.com to see 520 S Mashta Drive.

Questions About 520 S Mashta Drive

How much is 520 S Mashta Drive?: 520 S Mashta Drive is listed at $19,900,000, which is about $6,451 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 520 S Mashta Drive?: The listing reports annual property taxes of $201,741 for 2026. 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 520 S Mashta Drive built?: 520 S Mashta Drive was built in 1961 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 520 S Mashta Drive been on the market?: 520 S Mashta Drive has been listed for 42 days. Days on market and price changes are the first signals of how much room there is to negotiate.
Is 520 S Mashta Drive waterfront?: Yes. The listing describes the water as ocean access seawall bayfront. 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 520 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 520 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.

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Recently Sold Nearby

591 N Mashta Drive, Key Biscayne, FL 33149 · Sold $14,000,000 · 4 bd · 5 ba · 4,290 sq ft

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Nearby ZIP Codes

The 6 bedroom home at 120 Knollwood Drive, Key Biscayne, FL 33149 is comparable and listed for sale at $19,950,000. Another comparable home, 591 N Mashta Drive, Key Biscayne, FL 33149, sold for $14,000,000 in August 2026. Key Biscayne neighborhoods include Commodore Club and Ocean Club. 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.