One of So Cal's most beautiful boulder problems, the Fallen Arch climbs the prominent right-leaning corner just behind Where Boneheads Dare. The reason for its name is obvious, when you see the huge flake laying there at the base. It adds a bit of spook factor, although it's not really in the landing zone.
The rock to the left of the dihedral is black and the right side is white, making the climb look sort of like a yin-yang symbol. The idea of uniting opposing forces is apropos... Layback easily up till you can reach an obvious sloping dish on the lip, make a powerful and committing mantle, then delicately (desperately) get stood up on the dish and crank thin slab moves to the top.

On the south side of the boulder immediately behind (touching) Where Boneheads Dare.

up to you.