Today I went to Mustavuori to get a small hike and too see the tunnels and canyons.
I've been there, but I think long time ago... was like new for me. With a headlamp and rubber boots, it was nice to explore.
I also tested (again) multiflash photography in a cave-like environment... trying to practice.
But I wasn't sure if there was more than two tunnels, the Helsinki city map of the area seemed to say there was another one further to the north, but despite searching for it I didn't find more than a lot of trenches carved into the rock.
The coordinates of the two tunnels (with a canyon between their entrances) were N 60.23754 E 25.13905 and N 60.23748 E 25.13931.
At the back of the tunnel:
Photos (c) 2018 by Jari Arkko. All rights reserved.