This palace is on the edge of the Vltava (Moldau) River and when the famous floods of 2002 hit, this building (and this door) was at least half submerged...water was up to the top of this door. Seriously! Since that flood, the city developed and installed a system of removeable flood walls, unfortunately, due to the location of this building, the wall system is such that it passes in front of this building which means that if Prague were to have another flood like the one of 2002, this building would once again find itself underwater.
Given the fact that it was certainly badly damaged by water, we can only imagine that this door was either repaired with remarkable skill, or replaced. At first view I would bet on the latter, but when I look at it up close, it looks as if it has had a life longer than 8 years. Nevertheless, this beautiful door and simple, yet tasteful arch is a pleasure to look at.
I like how this big door becomes 2 as well as 4 doors. How? Well, 2 big doors, and in each of those doors, another smaller door! Cool, huh? I think so!