The Queenston Quarry was first opened during the construction of the Grand Trunk Railway to supply stone for new locks of the Welland canal (including the explorer favorite "Blue Ghost Tunnel"), and then from 1878-1881 by Hunter, Murray and Cleveland. After that the quarries were operated by P.A. Johnston (who was employing 75 men in 1890), and the land was owned by William M. Hendershot.
A small settlement of houses and a general store were built here as permanent quarters for the workers. The remains of at least three of these buildings can still be found here today. There are other foundation remains further north along the escarpment for those who wish to explore deeper into the bush.
The closest suggested parking to access this area is either at the dead-end of Melrose Drive to the west at N 43 9.237 W 79 5.727, or a pull-off at the bottom of the escarpment at N 43 9.530 W 79 5.027 (though quite a climb).
There are several other points of historic interest within hiking distance in this area. Please see these other OAP locations:
Queenston: Quarry Mine Entrance - Location #1773
Queenston: Cold War Antenna - Location #6333
Queenston: Cement Works - Location #6334