The boulevard at the Cosmo is by far the coolest venue I've been to. I went here to see Vampire Weekend perform and the atmosphere was perfect. The Cosmopolitan, to me, is already one of Las Vegas most hippest and trendiest Casinos. The Boulevard, is exactly the same. It is an rooftop venue, with some views of the strip. There are two pools! You don't even have to watch the band, you can swim and enjoy your cocktails while only listening to which ever band is performing. Also, you know how concerts always get uncomfortably hot, from all the breath and energy being projected. Well outside, you will at least get a little breeze to ward off the heat.