The sim's note says: "A festival of fire, art and community... in Second Life..." and it is. I know several people that do not budge from the sims of Burning Man for the whole duration of the Festival. It's a fun place, but very laggish... I only visited about half of it, it's not quite over yet, so hurry if you want to see it.
These builds were among my favourite places.
There is a lot more to see, many places I visited but did not take pictures of. Free items can be found as well, dancing places abound, live shows...