There are many places to enter the Wiss. Where you live will determine the most convenient place to enter, but that might not be the best if you have to park. Break-ins happen, and some parking lots are much riskier.
I park at the stables on Northwestern Ave and ride counter-clockwise. There are some maps on here or search the Rally in the Valley for the course map.
I park at the stables on Northwestern Ave and ride counter-clockwise.
This is where i drop in too. parking is kinda limited. But there are trailheads on the southern side of the park too. I think there is a bike shop in Philly that you can ride with on Sunday mornings. I've been meaning to check it out.