Right next to the Helsinki cathedral. Closed the day I visited unfortunatly - I've seen photos on the web and inside that dome it looks stunning
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/81269484@N00">JuliaC2006</a> from Rochester, UK
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/juliac2006/5089742728/">National library</a>