I'm going to be a bit controversial and confrontational here, but I say leave it to the ACTUAL pagans, rather than just go along because it's a bit new age-y and that sounds like fun.
Sorry, had to say it. My family are all pagans and get a bit fed up with people who have no actual belief in that treating it like some sort of festival or rave.
If you actually want to celebrate any solstice, equinox, or anything in between, get in contact with a local group and find out what they have organised or are going to as a group, don't just turn up at an ancient monument and expect to hijack it in to some sort of mass party, not everyone there is interested in having a wild time or a rave and you could ruin it for them. You can celebrate a solstice or equinox anywhere btw - pretty much just go out and look at dawn or sunset and appreciate it, you don't need to be anywhere special for it - nature has no cathedrals.
