Thought I'd dig out a couple classic photos from the original Woodstock. Here's Max Yasgur's farm, and the monument that now also marks the area, along with the original poster of the event. Special note, the festival wasn't originally free. Tickets were $18 in advance and $24 day/weekend of the festival. It wasn't until the crowd grew so large that festival organizers just stopped charging the fee, turning it into a free event for the late arrivals.
-DeadAir Dennis