Superior Hypogastric Plexus
This sympathetic plexus is made up of pre- and post-ganglionic fibers.  It lies in front of the aortic bifurcation and left iliac vein, and more distally, between the common iliac arteries.  It then lies on the bodies of L5 and S1.

Because of its location, it is vulnerable to approaches to the anterior aspect of this region.  Damage to the plexus can result in retrograde ejaculation.