Helsinki centre is hollow like a Swiss cheese. A great deal of the underground space is reserved for parking, but there are also many underground pedestrian connections and shopping malls. The Railway station, shopping malls Forum, Kamppi and City-Center and department store Stockmann are all connected to each other. This underground network extends From Kamppi all the way to Kluuvi and Kaisaniemi, but this connection is for service traffic only. If you go under ground here, you can (in theory) reach geocaches GCZG0F, GC23VEY, and some others too without popping up on the ground earlier than about 50 meters from the cache. But unfortunately pedestrians are not allowed to enter here.
The direct distance to GCZG0F is 410 m and to GC23VEY is 1072 m (the final coordinates, I am afraid you have to calculate it's location first). This time you have to do some calculations or drawings or alternatively just make a lucky guess... (You can check your guess here)
The location is quite public and the GPS coverage is quite poor at the site. I apologize your inconvenience... The coordinates have been taken from OpenStreetmap. NOTE! Please be careful, the cache box is in the middle of a street. Beware cars! The cache box is clearly visible from the right direction. D3 comes from the mystery part, the hide is quite obvious.
