A faux "beach"? Only in Vegas.
Met with friends here on the way to dinner - a friend had to sign us in. Unsure if there was cover, or if you had to be staying at Mandalay to gain admittance.
Had fun lounging on beach chairs, cooking in the sunny weather. It wasn't crowded at the time - late afternoon - yet there was still plenty of eye candy. Oh yes.
Bar drinks were pricey, but that fact shouldn't surprise anyone. Just knock back a shot or two to get a healthy buzz if you need one.