We entered the town square from the east and the first impression was stunning. The Holy Trinity Column dominates the whole square and is higher than the surrounding houses. I had already seen monuments of this kind in other Czech and Austrian cities and was also 'forewarned' by the previous reviews, nevertheless I was amazed. It is not only the sheer size that makes the column unique, but also the large number of sculptures, light-bearers and decorations. However, the appearance is harmonious and not exaggerated or disproportionate.
Of course, you can visit this site in about 10 minutes, but on closer look the first strong impression is even enhanced. We walked several times around the column and each time we noticed some more details. A table at the restaurant Caesar is perfectly suitable to admire the whole scenery of the square and the column. In the warmer months, there are tables just in front of the town hall. When visiting a town, I always like to get an impression from the bird's eye view. In Olomouc, I can recommend to climb the tower of the St Maurice Church close to the town square.
I clearly can support the recommendation of Ian Cade to spend more time in Olomouc. First, because the Holy Trinity Column is worth seeing at night. And second, because there is a real good night-life with nice restaurants and pubs in the cobbled streets of the old town and the university quarter.
A note for those who wants to travel to Olomouc in near future and also wants to see the Baroque fountains and the Plague column: in May 2012, there were construction works at the Dolni namesti. The building site extended almost over the whole square and we could view the Plague column and the two fountains only from distance. And the Mercury 's fountain was completely wrapped with plastic foil because of the renovation of a nearby building.