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Single Family Residence at 669 S Mashta Dr, Key Biscayne FL 33149Pending
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Single Family Residence
$5,799,000$1,715 / sqft

669 S Mashta Dr, Key Biscayne FL 33149

4
Bedrooms
4
Bathrooms
3,382 sqft
Interior
1960
Year built
None
HOA
Single Family Residence
Type

About this home

Located on the exclusive and highly sought-after Mashta Island, this exceptional property offers a rare opportunity to build your dream home or enjoy the existing beautifully refurbished residence. The home features new bathrooms, updated flooring, and tasteful modern finishes throughout. Designed for relaxed Florida living, the spacious covered terrace overlooks a stunning mosaic-tiled pool, creating the perfect setting for entertaining or enjoying the tropical surroundings. A unique opportunity in one of Key Biscayne's most desirable neighborhoods. Easy to show.

Features

  • Roman Tub
  • Split Bedroom
  • Volume Ceilings
  • Florida Room
  • Outdoor Shower
  • Garden

Location

Approximate — shows the building, not the unit. Open in maps (opens in a new tab)

Estimated loan & HOA

$29,323

Loan payment and HOA only. Property tax and insurance are significant here and are not included.

Principal & interest
$29,323
HOA
None

Illustration only — not a loan offer, quote, or commitment. Assumes a 30-year loan at 6.5% with 20% down (rates as of July 2026); your actual terms will differ.

Schedule a tour

Request a private or video tour with a local agent.

Courtesy of
Coldwell Banker Realty

Run the numbers

We fill in the price and the building's HOA dues. That leaves rent, tax, insurance and maintenance — they depend on your exemptions, your insurer and the unit, so we don't guess them. Vacancy and the loan terms below start at common defaults; change them.

Our default, not a market figure
From the listing
Depends on assessed value & exemptions
Varies widely by building
Repairs, turnover, management

Cap rate
Cash-on-cash
Monthly cash flow
Net operating income

Enter rent, property tax, insurance, maintenance to see the returns. A cap rate calculated without every cost overstates the deal — often by half — so we don't show a partial one.

Illustration only — not a loan offer, quote, or investment advice. The loan fields start at 20% down over 30 years at 6.5% (rates as of July 2026); that is a nominal rate for illustration, not an APR, and your actual terms will differ. Cap rate is unlevered; cash-on-cash counts the down payment as invested capital and excludes closing costs.

Listing data from the MIAMI Association of REALTORS® (MIAMIRE) IDX program. Information deemed reliable but not guaranteed. Demo data shown for layout purposes.