Seven Sisters Springs at the Chaz in Florida ! This was so cool you could go down about 10 to 15 feet into these holes and swim through these caves to the next opening. Since it was spring water it was clean , clear, and Pretty. 6 of the 7 caves/holes is easily doable, but ONE I would NOT recommend trying , much too tight , I almost got stuck in it. In any case it was sooo much fun to kayak to this place and swim in these underwater caves. with Get Up and Go Kayaking - Chassahowitzka
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https://www.youtube.com/watch?v=ROKcWgEFF68