Climate change is threatening ancient Greek monuments, among them the Acropolis, one of the most-visited archaeological sites in the world, scientists said.

Air pollution and acid rain are eroding marbles, while extreme weather phenomena such as droughts or torrential rains have led ancient walls and temples to develop structural problems.

Even though the Acropolis hill, where the Parthenon stands, is probably Greece's best preserved archaeological site, there are signs that climate change has been increasingly affecting the monuments that stand on the hill.

"The walls of the (ancient) city have more erosion than in the past," Maria Vlazaki, General Secretary of the Greek Culture Ministry, told Reuters.

The temple of the Parthenon on the rock of the Acropolis, located in the heart of Athens, dates back to the classical period of antiquity - the 5th century BC.

For decades there have been efforts to preserve and protect the Acropolis and its monuments, an operation that has been sped up since the mid 1970s.