Beautiful Cathedral of the Holy Family in Barcelona. This temple is being built to this day. At the time of 2017 it is planned that the final view of the cathedral will be acquired in 2026. However, when I was there, our guide said that the construction is very, very complicated, and such terms are too optimistic. All can last for another 40 years.
The construction itself was started in 1882. The cathedral has such a view, thanks to the most talented architect Antoni Gaudi. In 1926 he died, and now his work is transferred between the best architects, as a legacy. At the moment the church is 135 years old.
wow!