I've been this way many times, usually taking a wrong turn or a shortcut and noticed something which has seen it's raison d'être paved over by some interloper. I understand the right of way is owned by a group of interested parties, perhaps this is only a temporary lease and some day the sentinel will again be called into service. Til then it's a reminder of what once was a way of life and livelihood.
GZ is a busy hub during working hours, use stealth if visiting during the day.