MAIN KEY is a 145.5-acre private island with over a mile of pristine white sandy beaches on its east shoreline in Barnes Sound, Monroe County, FL. Its western and southern shoreline of over 4 miles of Mangroves reaching 30 to 50 feet tall provides a rookery that teams with gamefish, shellfish, sea mammals, and tropical birds. All owned by a TIIF Deed. With 12 upland acres, a substantial structure could be built with no ROGO requirements. In the 1930's and 40's, there were 3 large structures on the SE Government Lot area. A new dock permit with lift, platform, and mooring slip exists for the SE beach off the old homesite. An additional second permit is being applied for the south side of Main Key that will be 135 ft with a 40 ft platform and seven heavy pilings to moor a large vessel of up to 100 ft in length. A tide station was established by the USGS, later NOAA in the 1930's. 'The Tides at Main Key' was well known in Marine Weather forecasts on South Florida TV and NOAA Weather Radio for the Upper Keys and Florida Bay. Please contact the listing agents for more detailed information and documentation.
Vacant landProperty Type
145.5 acresLot Size
$27,113Price/Acres
Listed by KELLY SHAW PA• American Caribbean Real Estate, Christie's International Real Estate
Listed by Trent Shaw, PA• American Caribbean Real Estate, Christie's International Real Estate
As the MLS and public records start to fill up, we'll list the details here.
Public record
Public record
Zoning
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Style
Vacant Land
County
Monroe County
APN
00091640-000000
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Last updated by owner on Aug 24, 2026.
OS
I
Offshore Island District
The purpose of the OS district is to establish areas that are not connected to U.S. 1 as protected areas, while permitting low-intensity residential uses and campground spaces in upland areas.
Zone overlays
Industrial District
Permitted uses
Include but are not limited to:
Housing-Multiple units
Climate risks
1/10 Flood Factor
Minimal risk of a flood reaching the building in the next 30 years
1/10 Fire Factor
Unlikely to be in a wildfire in next 30 years
10/10 Heat Factor
7 days above 106° expected this year, 30 days in 30 years
10/10 Wind Factor
99% chance of strong winds in next 30 years
2/10 Air Factor
1 unhealthy days expected this year, 1 days in 30 years
Provided by First Street
Historical weather
Key Largo, FL • 33037
Average low and high temperatures (°F)
73
62
75
66
78
70
80
74
85
79
86
81
86
81
88
81
87
81
83
77
79
72
77
68
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Jun
Jul
Aug
Sep
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Sun exposure
100/ 100
Exceptional sunlight
Sunscore
This home ranks in the top 1% for direct sun exposure in Key Largo. There appears to be minimal shading by surrounding buildings, terrain, and vegetation.
9.5 hrs
7.3 hrs
JuneDecember
Provided by Shadowmap
Redfin Estimate for Main Key, Barnes Sound
$3,350,660
$594K under list price of $3.95M
Nearby comparable homes
The Redfin Estimate uses 6 recent nearby sales, priced between $1.1M to $3.9M.