$18,500,000
631 N Mashta Drive
Key Biscayne, FL 33149
MLS# B26058354
4 beds  |  5 baths  |  3720 sqft


Aerial
  1 / 49  
Aerial house driveway Back of the house Back of the house Aerial Aerial Aerial Aerial Aerial 5-web-or-mls-DSCF0278 6-web-or-mls-DSCF0281 7-web-or-mls-DSCF0287 8-web-or-mls-DSCF0291 11-web-or-mls-DSCF0299 12-web-or-mls-DSCF0304 13-web-or-mls-DSCF0306 14-web-or-mls-DSCF0293 15-web-or-mls-DSCF0310 17-web-or-mls-DSCF0314 18-web-or-mls-DSCF0318 20-web-or-mls-DSCF0323 21-web-or-mls-DSCF0326 22-web-or-mls-DSCF0331 23-web-or-mls-DSCF0333 24-web-or-mls-DSCF0336 25-web-or-mls-DSCF0338 26-web-or-mls-DSCF0341 27-web-or-mls-DSCF0344 29-web-or-mls-DSCF0350 30-web-or-mls-DSCF0355 31-web-or-mls-DSCF0356 32-web-or-mls-DSCF0363 33-web-or-mls-DSCF0359 34-web-or-mls-DSCF0365 35-web-or-mls-DSCF0370 36-web-or-mls-DSCF0372 37-web-or-mls-DSCF0374 38-web-or-mls-DSCF0377 39-web-or-mls-DSCF0380 41-web-or-mls-DSCF0386 42-web-or-mls-DSCF0389 43-web-or-mls-DSCF0393 44-web-or-mls-DSCF0395 45-web-or-mls-DSCF0398 47-web-or-mls-DSCF0406 48-web-or-mls-DSCF0407 1-web-or-mls-DSCF0267 2-web-or-mls-DSCF0270

Property 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

Details
Maps
Contract Information
Comp Sale YN: No
Listing Date: 2026-07-29
Status: Active
Original List Price: 18500000
List Price: $18,500,000
Current Price: $18,500,000
Occupant Type: Vacant
Listing Service: Full Service
Location and Legal
Country: United States
County Or Parish: Miami-Dade
Street Number: 631
Street Direction Prefix: N
Street Name: Mashta
Street Suffix: Drive
Municipality Type: Incorporated
Municipal Code: 24
State Or Province: FL
Postal Code: 33149
Postal Code +4: 1720
Subdivision Name: MASHTA ISLAND
Area: 2520
Geographic Area: DADE
Elementary School: Key Biscayne K-8
Middle Or Junior School: Ponce De Leon
High School: Coral Gables
Special Assessment YN: No
Parcel Number: 2452050080070
Zoning: 2001
Flood Zone: AE
General Property Information
Property Sub Type: Single Family Residence
Bedrooms Total: 4
Bathrooms Total: 5
Bathrooms Full: 4
Bathrooms Half: 1
Building Area Main: 3720
Building Area Source: Public Records
Living Area Main: 2255
Living Area Source: Public Records
Adjusted Area Main: 2779
Accessibility Features YN: No
Year Built: 1958
Carport YN: 1
Attached Carport YN: Yes
Carport Spaces: 2
Covered Spaces: 2
Parking Total: 8
Gated Community YN: No
Lot Size Area: 15000
Lot Size Acres: 0.34
Frontage Length: 100
Senior Community YN: No
Waterfront YN: 1
Water Frontage Feet: 100
Outdoor Living Spaces YN: Yes
Stories Total: 1
Stories: 1
Direction Faces: East
Fireplace YN: No
Pool Private YN: Yes
Green Verification YN: Yes
Furnished: Unfurnished
Financial Information
Application Required YN: No
Master Association YN: No
Membership Fee Required YN: No
Tax Annual Amount: 112485
Tax Year: 2025
Tax Legal Description: MASHTA ISLAND PB 60-93 LOT 7 BLK 1 LOT SIZE 100.000 X 150 OR 17980-3315 0198 4
Leasing Permitted Details
Leasing Permitted YN: No
Parking Information
Open Parking Spaces: 6
Boat and Dock Information
Dock: Yes
Main Level Rooms
Main Level Bathrooms: 4
Main Level Bedrooms: 4
Pet Details
Pet Fee YN: No
Storm Protection
Impact Glass: Complete
Room Types
Dining Room Level: Main
Kitchen Level: Main
Living Room Level: Main
Master Bedroom Level: Main
Price Calculations
Current Price To SqFt: 8203.99
Status Change Information
Major Change Timestamp: 2026-07-30T18:40:51Z
Major Change Type: New Listing
Status Change Date: 2026-07-30
Originating Details
Originating System Key: 20260729170810306019000000
Originating System ID: M00000170
Property Features
Dining Area: Dining/Living Room
Exterior Features: Garden; Private Rooftop Terrace
Flooring: Concrete; Laminate; Tile
Parking Features: Circular Driveway; Driveway; Attached Carport; Carport
Property Condition: Resale; Updated/Remodeled
Special Listing Conditions: Standard
Appliances: Dishwasher; Dryer; Electric Cooktop; ENERGY STAR Qualified Dishwasher; ENERGY STAR Qualified Dryer; ENERGY STAR Qualified Freezer; ENERGY STAR Qualified Refrigerator; ENERGY STAR Qualified Washer; Free-Standing Freezer; Microwave; Oven; Refrigerator; Washer; Water Heater; Wine Refrigerator; Cooktop
Water Heater Details: Electric Water Heater
Boat and Dock Features: Electric Available; Private Dock
Construction Materials: Brick; Concrete
Cooling: Central Air
Green Energy Efficient: Appliances; HVAC
Heating: Central; Electric
Interior Features: Entrance Foyer; Walk-In Closet(s)
Laundry Features: Inside; Laundry Room; Sink
Listing Terms: Cash; Conventional
Membership: No Membership Available
Pets Allowed YN: Yes
Pets Allowed: No Restrictions
Pool Features: Equipment Included; In Ground
Possession: Close Of Escrow; Negotiable
Restrictions: See Remarks
Roof: Shingle
Sewer: Public Sewer
Sprinkler Description: Auto Sprinkler; Zoned Sprinkler
Structure Type: House
Tax Information: City/County
Utilities: Electricity Connected; Sewer Connected; Water Connected
View: Pool; Water
Water Access: No Fixed Bridge; Ocean Access
Water Source: Public
Water View: Bay; Intracoastal
Waterfront Features: Bayfront; Intracoastal; Navigable Water; Seawall
Window Features: Storm Window(s)
Showing Requirements: 24 Hour Notice; Call Listing Agent
Outdoor Living Spaces: Patio
Patio Details: Patio - Covered; Patio - Open
Room Types: Dining Room; Kitchen; Living Room; Master Bedroom
Acreage Description: 1/4 To Less Than 1/2 Acre Lot; Less Than 1 Acre Lot
Supplements
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.
Room Information
Room Name Length Width Level
Living Room16.0022.00Main
Kitchen12.0011.00Main
Master Bedroom25.0020.00Main
Dining Room12.0014.00Main

IDX
Listing Office: Coldwell Banker
Source MLS Verified

Last Updated: October - 20 - 2026

This information is not verified for authenticity or accuracy and is not guaranteed and may not reflect all real estate activity in the market. Copyright 2026 Beaches Multiple Listing Service, Inc. All rights reserved. Information Not Guaranteed and Must Be Confirmed by End User. Site contains live data.


Scroll to Top