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631 Mashta, Key Biscayne, FL

Offering:
For Sale
Location:
Key Biscayne, FL 33149
Subdivision:
MASHTA ISLAND
Status:
Active
Number of Bedrooms
4
Number of Bathrooms
5
Living Area sq ft
2,255 sq ft
$18,500,000

Deemed reliable but not guaranteed.

Details
Year built:
1958
Lot size:
0.34 acres · 15,000 sq ft
Levels:
One
Stories:
1
Rooms:
4
Parking:
8 spaces · 2 covered
Condition:
Updated Remodeled
Faces:
East
Days on market:
73
Annual tax (2025):
$112,485
Type:
Single-family home
MLS ID
B26058354
Virtual tour:
Listed by:
Coldwell Banker (FLL606111)
Listing office phone:
561-395-2233
Listing office email:
Listing agent:
Javier Gustavo Quiroz (FLL276804194)

Features

Dual Sinks
Entrance Foyer
Living Dining Room
Walk In Closets
Built In Oven
Dryer
Dishwasher
Electric Water Heater
Freezer
Microwave
Refrigerator
Self Cleaning Oven
Wine Cooler
Washer
Impact Glass
Patio
Brick
Block
Composition
Shingle
Less Than One Acre
Quarter To Half Acre Lot
Sprinklers Automatic
Sprinkler System
Intracoastal Access
Navigable Water
Ocean Access
Seawall
Schools
Elementary:
Keybiscayne
Middle / junior:
Ponce De Leon
High:
Coral Gables

School assignments come from the MLS feed and can change. Verify with the district before relying on them.

Association
Amenities:
Boat Dock, Pool
Pets
Allowed:
no
Utilities
Available:
Electricity Available, Sewer Available, Water Available
Water source:
Public
Sewer:
Public Sewer

Description

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.
Price history
$18,500,000 → $18,500,000 · 1 price changes

Location

631 N Mashta Drive
Key Biscayne, FL 33149

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MLS information

Last updated Oct 10, 2026

IDX information is provided exclusively for personal, non-commercial use, and may not be used for any purpose other than to identify prospective properties consumers may be interested in purchasing. Information is deemed reliable but not guaranteed.