15grams settles into Marquee Dayclub's sun-soaked pool deck at The Cosmopolitan, where the crowd trades the desert heat for cool water and cold cocktails. Expect the usual dayclub rhythm here — beats rolling out over two pools, cabanas stocked with bottle service, and that easy mix of lounging and dancing that defines a Vegas pool party. Guests can post up poolside on a general admission basis or lock down a table for a more curated setup with dedicated service.

The space itself does a lot of the work — infinity-edge dipping pools in the grand cabanas, flat screens, a food and drink menu built for grazing between dips in the water. It's the kind of afternoon where the line between lounging and partying blurs, with DJs keeping the energy moving as the sun arcs overhead. Come 21 or older, ready to soak in both the rays and the sound.