I went to Johnny Cay 4 times in my week stay in San Andres. It is by far the nicest beach and the sea is gorgeous and clean and easy to swim in. There isn't much to do on the island, it is very small. But if you just want to chill out and relax then it's perfect. There is a banana boat ride you can do, and there is some cool wildlife to see, iguanas and spiders etc. The food/drink huts are good and fairly cheap. Lots of reggae music and nice friendly atmosphere made it a really nice place to relax for the day. Boat rides are cheap to get there and back and its very close to San Andres. Definitely go here!
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