The Foundation, in particular its Construction division, operates out of a top-secret location known as “Base μ”. It is located on the border between the regions of Bridgia and Gilnar, on vaguely the western side of the Bridgeland.
However, the Foundation is known to move frequently. It originally resided in its namesake, Bridge Base, but has occupied ten sites in total:
Becoming a member of the Foundation is easy, really. Due to the shifting sands of Bridgian society, you don’t have to physically attend the Base anymore to gain membership: most of its work has moved online in recent years.