Erechtheion Caryatids: in 1979 "The Caryatids of Erectheion were replaced by the Greek government with replicas, to protect the originals from the pollution of the city. The original Caryatids are now exhibited in the new Acropolis Museum, with one empty space for the return of their sister from the British Museum." ("Acquired" by Lord Elgin in 1801 along with the "marbles")
See greektraveltellers.com

"Almost all the statuary adorning the cathedral today are copies. The originals are kept in the Crypt of the Statues in the Museo dell'Opera del Duomo."
See en.wikipedia.org

The statue of Jean de La Grange, damaged by erosion and pollution, was removed from the "Beau Pilier", a buttress of the north tower decorated with statues of eminent figures of the kingdom of France from the end of the 14th century, in 2003-2004 and replaced by a copy. It was restored in 2006. Since then, it has been kept at the Musée de Picardie in Amiens. - The front of the trumeau of the Saint-Honoré portal, is occupied by the statue of the Golden Virgin, a masterpiece of the 13th century. The original statue, threatened by bad weather, was transferred inside the cathedral in 1980 and replaced by a cast.
See fr.wikipedia.org

Some of the statues in the Tuileries Gardens have been replaced by replicas. Some of the originals can be found in the Louvre, e.g. "Lion au serpent". Other originals have been returned to the museums or parcs where they were beforehand, e.g. the Farnese Hercules in the parc of the Castle of Sceaux
See fr.wikipedia.org

The Stelae known as "Los Danzantes": "On the main level of the platform you will see carved stones depicting men captured in war. Called Los Danzantes, or dancers, these are replicas. The originals are in the museum on site and in the National Anthropology Museum in Mexico City."
See oaxacaculture.com

Michelangelo's Statue of David: "In 1910, the statue of David that was exposed to the elements in Piazza della Signoria, was transferred to the Accademia Gallery to avoid its deterioration, and the David we currently see at the square is a copy of the original."
See www.florence-museum.com