Saying that there's "no real beach" at Hidden Beach isn't exactly accurate- it's more that the reef is close there, and so it's not a good swimming/ water access spot. I'm not sure if this link will work, but you can go to Google Maps and virtually "walk" down the beach (it's just past high tide) to see what it's like. Here's the whole link to copy and paste in your browser (don't just click on the hyperlinked part): https://www.google.com/maps/@20.4540563,-87.2716841,3a,75y,49.09h,74.59t/data=!3m6!1e1!3m4!1sIEn6aFnniXf0rKMV6HmY3w!2e0!7i13312!8i6656!6m1!1e1

I'd guess it's about 300 yards long. Nice to go back and forth from there to the pool. If you want nice water access, you have to put on clothes and go to the sister resort next door. Or- rent a car and drive down to Tulum/ the Biosphere.

-nd.