Sombrero Beach, Marathon
Sombrero Beach is a beautiful beach with facilities, and parking. Bring your own food and drinks as there are no food vendors there. From Rt. 1 (go south from the condo) turn left at the light right before PUBLIX, and drive apron 1.5 miles. No fees.
Bahia Honda State Park
Bahia Honda State Park every year is on the Top 10 Beaches in the USA. There is a bay side swimming and an ocean side- so depending on your prefrence, you always have a great place to get some rays and swimming. There are facilities, plus a gift shop and luncheonette. Since you can rent kayaks right there, along with exploring one of the most beautiful beaches, expect to spend the whole day there. Get there early-9-10 am if possible. Small fee since it is a State Park.
Inch Beach on Key Colony Beach
Inch Beach is a private beach. It all started years ago when a gentleman saw that the oceanfront land was being bought up for condos, closing access to the beach. He bought the land, then sold 160 shares hence the name "Inch Beach"...those who bought a share own about a square yard and have a deed to their land. Since it is only available to those who purchased their "inch" , if you are lucky enough to rent a place that offers Inch Beach you can then use the beach.