#9 – Catherine Palace, Russia
This palace from the 18th century will certainly raise your eyebrows once you see how enormous it actually is. It was once a summer residence for emperors of Russia, and it took over 30 years for it to be constructed. Construction was finished in July 1756. Very rich materials were used to construct this building, including more than 100 kilograms of gold, which was used on certain parts of the palace that you can still see shining today.