In traveling through Europe, there are lots of places, buildings, etc. which are reconstructions.
World War II created a lot of damage to historic sites and these were for the most part rebuilt in the years following the war. Dresden is a prime example. When I first visited East Berlin in 1964, many of the historic buildings were still in ruins.
Now (since the reunification), these have been reconstructed. Should you visit Monte Cassino in Italy, that is a total reconstruction after being bombed by the Allies during WWII in a controversial
action.
Usually when reading up on places to visit, you
will find out about these reconstructions. What may not be pointed out however are the repairs, etc. that
have been made over the years. Especially in modern times, pollution has caused an enormous amount of damage to old buildings and monuments. It is like your house: constant repair and upkeep.
In certain cases, where feasible, the original
has been replaced by a replica and the original moved to a safer locaton under climate controlled conditions. This is true of the Marly horses in the Place de la Concorde in Paris which now reside inside the LOuvre with replicas in their original location. In the Musee D'Orsay on the ground floor, you will find a wonderful sculpture removed from the facade of the Opera House for preservation reasons.
There are original sculptures from the facade of Notre Dame residing in the Musee du Moyen Age...although in this case, I believe they were removed during the Revolution by the rebels and later found. Everyone is upfront about these substitutions.
Time does take its toll!!!!