I had the same feeling when I saw it years ago. Dread, sadness, and a sinking stomach.

A few weeks ago I was vacationing in the Basque country, and realized Guernica (the town) was a mere half hour drive away. So we went. Although none of the town in any way reminds you of the depictions of the painting (save for some memorials), I kept feeling the same eerie dread even as I walked through a perfectly normal, pleasant sleepy town.