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631 N Mashta DriveKey Biscayne, FL 33149

For Sale

$18,500,000

Smart Buyer Rebate $185,000

BRING ALL OFFERS! Exceptional waterfront opportunity in prestigious Key Biscayne. Set on a 15,000 sq. ft. lot with 100 feet of water frontage, this residence offers open-water views, direct Biscayne Bay access, and no fixed bridges to the ocean. Currently undergoing a complete renovation, it will feature modern finishes, impact windows and doors, new systems, spacious living areas, a chef's kitchen, and luxurious bathrooms. Enjoy a private dock, deep-water access, pool, breathtaking sunsets, and an unmatched boating lifestyle in one of South Florida's most desirable communities One of the most compelling waterfront opportunities currently available in all of Key Biscayne. Perfectly positioned on the exclusive and highly coveted Mashta Island, this exceptional property offers approximately 100 feet of prime waterfront, deep-water dockage, direct Biscayne Bay access, and no fixed bridges to the Atlantic Ocean, creating an unparalleled opportunity for boating enthusiasts and yacht owners. Mashta Island has long been recognized as one of South Florida's most prestigious residential enclaves, offering exceptional privacy, quiet tree-lined streets, oversized waterfront estates, and immediate access to the open waters of Biscayne Bay while remaining only minutes from Brickell, Downtown Miami, Coconut Grove, Coral Gables, Miami Beach, and Miami International Airport. Very few neighborhoods offer this combination of island living, security, boating lifestyle, and proximity to the city's financial and cultural centers. The residence is currently on renovation designed to transform the property into a contemporary waterfront estate while preserving the exceptional value of its location and oversized waterfront parcel. This is substantially more than a cosmetic renovation. The project includes major improvements throughout the residence, including redesigned living spaces, upgraded electrical and plumbing systems, new HVAC equipment, impact-resistant windows and doors, premium flooring, modern architectural lighting, designer finishes, and a completely reimagined interior intended to meet today's luxury lifestyle expectations. Upon completion, the home is anticipated to offer spacious entertaining areas, beautifully appointed bedroom suites, bathrooms, an impressive chef's kitchen featuring custom cabinetry, premium appliances, elegant countertops, and thoughtfully designed indoor-outdoor living spaces that maximize the spectacular waterfront setting. The property's exceptional orientation provides beautiful water views and unforgettable sunsets while creating an ideal environment for entertaining, family gatherings, and year-round outdoor living. The expansive backyard offers generous space surrounding the swimming pool together with multiple areas for outdoor dining, lounging, and enjoying the waterfront lifestyle that has made Key Biscayne one of the most desirable residential communities in South Florida. For boating enthusiasts, few properties can offer the combination of oversized waterfront, private dockage, deep-water access, and unrestricted navigation to Biscayne Bay and the Atlantic Ocean without fixed bridges. Whether accommodating a large sport yacht, cruising yacht, center console, or multiple vessels, the waterfront configuration provides flexibility rarely available in today's market. Key Biscayne continues to be recognized as one of South Florida's most exclusive island communities, celebrated for its pristine beaches, excellent schools, private clubs, marinas, tennis facilities, parks, bicycle paths, restaurants, and relaxed coastal lifestyle. Residents enjoy the unique advantage of living within a peaceful island environment while remaining only a short drive from Miami's world-class shopping, fine dining, cultural institutions, private airports, international business centers, and professional sports venues. The supply of premium waterfront homes on Mashta Island remains extremely limited due to the neighborhood's established character and finite number of waterfront parcels. As a result, opportunities to acquire large waterfront lots with substantial dockage and direct ocean access continue to be highly sought after by both domestic and international buyers. The combination of location, waterfront dimensions, boating accessibility, oversized lot, and comprehensive renovation creates a property with exceptional long-term appeal. Showings are strictly by appointment with the Listing Agent.. All measurements, dimensions, lot size, square footage, waterfront frontage, dock dimensions, room sizes, zoning, taxes, permits, specifications, plans, renderings, and property information are believed to be accurate but are not guaranteed and should be independently verified by Buyer. Renderings, conceptual plans, floor plans, specifications, and construction updates are available upon request when applicable. This offering represents an extraordinary opportunity to secure one of Key Biscayne's waterfront residences . Whether as a primary residence, seasonal retreat, or long-term investment, this property combines one of South Florida's most desirable locations with an outstanding boating lifestyle and exceptional future value. Bring All Offers.

Listed by Javier Gustavo Quiroz

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License #FLL276804194

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Coldwell Banker

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305-909-5940

Last updated July 31, 2026

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Source: MIAMIRE #B26058354

Listing Facts

  • TypeSingle-family
  • NeighborhoodVillage of Key Biscayne
  • Bedrooms4
  • Days on Prevu3
  • Taxes$112,485/year
  • Size2,255 sqft
  • Price per sqft$8,204

Amenities

  • Dishwasher
  • Private Outdoor Space
  • Washer/Dryer
  • Pets Allowed
  • Air Conditioning
  • Parking
  • Swimming Pool

Location

Mortgage Calculator

Listing History

07/29/2026
Listed by Coldwell Banker
$18,500,000

Property Details for 631 N Mashta Drive

Association

Amenities

  • Association Amenities: Boat Dock, Private Pool
  • Pets Allowed: Yes

Exterior

Construction

  • Property Condition: Substantially Remodeled, Updated/Remodeled, Completely Renovated
  • Roof: Comp Shingle Roof, Shingle
  • Stories: 1
  • Stories Total: 1
  • Structure Type: House
  • Window Features: Complete Impact Glass
  • Year Built: 1958
  • Year Built Details: Resale
  • Construction Materials: Concrete Block Construction, Brick
  • Entry Location: Foyer

Features

  • Direction Faces: East
  • Other Structures: Livable
  • Patio And Porch Features: Patio
  • Pool Features: Equipment Stays
  • Pool Private: Yes
  • View: Bay, Intracoastal View, Pool, Water, Bay View
  • Waterfront Features: Intracoastal Front, Navigable Water, Ocean Access, Seawall
  • Waterfront: Yes

Measurements

  • Building Area Total: 3,720
  • Building Area Units: Square Feet
  • Frontage Length: 100
  • Lot Features: 1/4 To Less Than 1/2 Acre Lot, Less Than 1 Acre
  • Lot Size Acres: 0.34
  • Lot Size Square Feet: 15,000
  • Lot Size Units: Square Feet

Financial

Taxes

  • Parcel Number: 24-52-05-008-0070
  • Tax Annual Amount: $112,485.00
  • Tax Year: 2025

Interior

Features

  • Appliances: Electric Water Heater, Dishwasher, Dryer, Free-Standing Freezer, Microwave, Refrigerator, Self Cleaning Oven, Wall Oven, Washer
  • Flooring: Concrete, Tile
  • Interior Features: Entrance Foyer, Walk-In Closet(s)

Measurements

  • Living Area: 2,255
  • Living Area Units: Square Feet

Rooms

  • Bathrooms Full: 4
  • Bathrooms Half: 1
  • Bedrooms Total: 4
  • Rooms Total: 4

Other

Environmental

  • Green Energy Efficient: Appliances, HVAC

Location

  • Subdivision Name: MASHTA ISLAND

Parking

Parking

  • Attached Garage: Yes
  • Carport Spaces: 2
  • Covered Spaces: 2
  • Open Parking: Yes
  • Parking Features: 2 Or More Spaces, Circular Driveway, Driveway
  • Parking Total: 8

Schools

Elementary School

  • Elementary School: Keybiscayne

High School

  • High School: Coral Gables

Middle or Junior School

  • Middle Or Junior School: Ponce De Leon

Utilities

Equipment

  • Cooling: Central Air
  • Has Cooling: Yes
  • Heating: Central, Electric
  • Has Heating: Yes
  • Sewer: Public Sewer, Public Sanitation, Sewer
  • Utilities: Electricity Available, Sewer Available, Water Available
  • Water Source: Public

Frequently Asked Questions

How many bedrooms does this single-family home have?

There are 4 bedrooms in this single-family home at 631 N Mashta Drive.

What schools are nearby to 631 N Mashta Drive?

Nearby schools include the Keybiscayne Elementary School, Ponce De Leon Middle School, and Coral Gables High School.

Does this single-family home have parking?

Yes, there are 8 parking spaces available for 631 N Mashta Drive.

What are the annual taxes for 631 N Mashta Drive?

Annual taxes for this single-family home are estimated at $112,485.

How does 631 N Mashta Drive compare to other single-family homes in Village of Key Biscayne?

This single-family home is listed 338% above the average price for single-family homes in Village of Key Biscayne and has been on the market for 84 less days than the typical home in this area.

What is the square footage on this single-family home?

According to the MLS, this listing is 2,255 sqft.

631 N Mashta Drive is a 4-bedroom single-family home for sale in Key Biscayne FL 33149. Listed on Prevu for 3 days at $18,500,000. This property features 2,255 square feet of living space, located in Village of Key Biscayne. The median listing price for single-family homes in this area is $2,287,500. Nearby schools include Keybiscayne Elementary School, Ponce De Leon Middle School, and Coral Gables High School. Property amenities include private outdoor space, dishwasher, pets allowed, air conditioning, parking, swimming pool, and washer/dryer. Browse more single-family home listings in Key Biscayne.

Based on information from Miami Association of REALTORS and/or other sources. All data, including all measurements and calculations of area, is obtained from various sources and has not been, and will not be, verified by Prevu or the MLS. Information is provided exclusively for consumer's personal, non-commercial use and may not be used for any purpose other than to identify prospective properties consumer may be interested in purchasing.

Full MLS Disclaimers

Rebate estimate is indicative only and based on listing price and estimated buyer's agent commission paid by owner, if applicable. Final rebates are subject to Terms of Use and may vary due to final negotiated transaction terms.