Well, I personally wouldn't mind if the parade would be held up here in Finland one day.
But if you're into BIG guns there are two 2 x 305mm coastal cannons built into two of the islands (Kuivasaari, Mäkiluoto) surrounding Helsinki. At least Kuivasaari is fully functional. First fired in 1935, put out of action in the 70's and then restored to it's former glory in the 90's. They fired it with blanks a few weeks back but gonna go live on December 6th (for our 85th year of independence).
The gun is huge. Just the barrel of the gun weighs over 60 tonnes and the ammo half a tonne a piece. A guy they interviewed said the momentary (for four hundreths of a second) need for power to get the "ammo" moving amounts to 4 Gigawatts!
Well OK, not everyone may be that impressed (but I was) and yeah, it's outdated by modern weaponry but still if anyone is interested...
http://www.rt-kilta.net/english.html
Jäger27
*Picture property of SA-kuva