User blog comment:HarmonyBass/Destiny Ramblings: The Vex and why they haven't won yet. (WARNING! MIGHT GIVE YOU A HEADACHE!)/@comment-25932172-20170609014644/@comment-160529-20170611144633

If you want a source... fine... I will find a source.

Oh by the way, after the Black Garden was brought into normal space... http://destiny.wikia.com/wiki/Tenebrous_Tunnels it could literally be tunneled into via normal non-magical and non-sciency tunnels... like, via manual digging