Helsinki - sights worth seeing?

[antspants]

I've got a meeting in Helsinki next week and expect to have one evening to myself while I'm there.

Are there any sights worth seeing that really shouldn't be missed while I'm in town, as I confess to knowing very little about the place?

[Dave_ITR]

I remember going to Senate Square, impressive Cathedral on one side & parliament buildings on another.

Went to a traditional Russian restaurant called Saslik, ignoring the decor the place was excellent, really good food.

Temppeliaukio Kirkko (a church carved & built into a rock) was pretty impressive.