Built 1894-1900 under the order of Tsar Nicholas III, this Russian Orthodox cathedral was truly magnificent both inside and out. Unfortunately, photos were prohibited (as seems to be the case with most churches in Tallinn) and the exterior is undergoing restoration.
I hiked up the hill so many times to try to get the "perfect" shot of this cathedral -- my favorite building in Tallinn -- that I decided to post some of them so the effort won't have been in vain ;-). I'm not sure any of them was perfect, although the first one I posted is still my favorite http://www.pbase.com/helenpb/image/143889955