If you enjoy beautiful secluded beaches, Bahia Honda State Park is the place to go. The clear water and peaceful atmosphere makes you feel as if you are on your own island. The water is perfect for wading and in certain spots it is great for swimming as well. There is also interesting wildlife that is a draw as well. When I was there I saw many iguanas and also different types of colorful fish as well.
When you arrive at Bahia Honda you will have to pay an entrance fee which is usually by the carload if I remember correctly. Once you leave the entrance you will have the choice to turn either right or left. If you take a right you will head towards the busier beach and also the access to the old bridge. If you take a left it will take you to the secluded beach. Follow it all the way to the last parking lot. The further you walk along the beach to the left, the more secluded you will get...the beach can get busy near the parking entrance.
Do some research before you go - at certain times of the summer the beach becomes full of seaweed that has accumulated due to a natural process and it is impossible to actually use the beach.