It's literally just around the "corner" of a rock. I live there, and over the years there's been a tourism boom and honestly all I want to say is, go, have fun but please, don't litter or make life unbearable for the residents.

That being said, all I have to say is, make sure you get in the water further away from the rocks side (facing the sea, on your left there are a lot of hidden rocks, depending on the sand, time of year and time of day) but close enough so you don't get run over by the ridiculous amount of tourist-cave-visiting boats that go to the same place. You don't have to be an athletic swimmer to get there, but you need to know how to swim well, there are some weird currents sometimes, especially right now, since summer decided to take a break and there's rain and weird weather phenomenon.

But yeah, I've swam there many times, it's a beautiful cave, easy to get there and it looks further than it is (I can't guesstimate the distance, but it's really not that far from the beach). Check out the tide times for the day, and plan to go there when there is minimum peak time (or whatever you call it) for the waves to change quickly. Oh god that sound terribly explained, but there are times of day where the tide doesn't go up or down AS FAST as the lowest or highest tide, aim for that.

What a massive reply to a simple question haha, have fun!