Complex sentence: In the Netherlands, the "Amsterdammertjes" of Amsterdam, first erected in the 19th century, became popular symbols of the city, although they are now gradually being removed and replaced with elevated sidewalks.
Split into simpler sentences: In the Netherlands, the "Amsterdammertjes" of Amsterdam were first erected in the 19th century. They became popular symbols of the city, but they are now gradually being removed and replaced with elevated sidewalks.