I visited the 3rd largest city in the Czech Republic, Ostrava, located in the north-eastern area that is close to Polish border. I was there just to take photos of the National cultural landmark, including Hlubina coral mine, coking plant, and blast furnaces. They are located in Vítkovice.
Although it was only a night stay there, I visited twice - daytime and at night. When buildings were lit up after the sunset, they looked like Moon base. When I got off tram at Vítkovice vys. pece, I immediately fell in love with the area!!! The view was just breathtaking.
When I was there, there was a opera concert taking place. I am not sure if you can see an audience in the photo below. As I did not have a ticket I could not walk around during the concert... Well, I should not complain because I could take photos by listening to opera songs as BGM. It was free of charge.
Although I haven't explored Czech Republic yet, Vitkovice is by far my favorite place! I promised myself to visit there once again, expecting that there is no more events.