A while back, I came across a really interesting image. I'll link it here for reference, as that site comes with a few secondary details, but I'll place a copy of the image in the gallery for those wishing to skip the third party site. Opening it in a new tab may provide better details. Several well-known structures are visible in the old image, like Hog's Back Bridge and Falls down at the bottom, with the merry-go-round-looking-roof pavillion. Riverside Drive is there and you can see it pass beneath the large bridge which has since been reconstructed as the George Dunbar Bridge for the south end of Bronson. You can even see the outlines of the parking for Vincent Massey Park just above the centre of the image. The old quarry is the rectangular-looking pond to the right with the tall walls visible on two sides.
Based on the presence of certain things and the absence of others like Carleton University or the Sir Charles Tupper Building, the lack of leaves or snow, and the apparent spring-level water in the river, this image is likely from late spring, between 1956 and 1958.
Just for fun, I was able to get a similar modern view from Bing maps and I've placed it in the gallery for comparison, though geocaching reduced the quality. This link may allow for a better view and the ability to further manipulate the image. The Tupper Building is now the prominent feature on the SW corner of the Heron/Riverside intersection and the quarry is completely invisible, hidden by trees. What other fun similarities and differences you can spot in the two images? Maybe some detectives out there can figure out the exact year?
As for the cache itself, I placed it in the old quarry to help folks get the rare "abandoned mine" attribute. My research says that the rocks taken from here were used in the construction of Hog's Back dam. The rock face is quite tall and I considered making an earthcache for it, but I couldn't figure out an interesting lesson based on what I saw there. Be patient with the GPS signal. If you're getting too much signal bounce, find the old green fencing on the ground and then look in the trees near the rock wall nearby.
I should add that there is evidence of at least one campsite in the broader area around the quarry. We didn't see anyone in the quarry, but there are some worn trails that even show up on trail maps. It's kind of a dead-end for hiking so who knows why it gets much foot traffic, but I would personally recommend visiting during the daytime and with a friend out of an abundance of caution. Besides, there is also the very slight potential for falling rocks from the quarry wall. I hope you enjoy the adventure and then take in the wonderful scenery in the area.