(CNN) -- Labeled "degenerate" by Hitler's Nazi Party and thought to have been destroyed in the lead up to World War II, eleven sculptures are back on display in Germany.

The bronze and terracotta works, by artists including Otto Baum, Edwin Scharff, Emy Roeder and Marg Moll were discovered during excavation works for a new metro line opposite Berlin's Town Hall earlier this year.

Not seen in over 70 years, the sculptures are now considered treasures of classical modernism.

Seized from galleries and museums by the Nazi Party's propaganda ministry in the 1930s, the term "degenerate" was given to almost all forms of modern art and banned under the premise that they were "un-German."

The works were featured in the Nazi's 1937 "Degenerate Art" exhibition, which toured Germany, coinciding with an exhibition of "Great German Art."

Matthias Wemhoff , Director of the Neues Museum, Berlin, where the sculptures are now on display, said the point of the exhibitions was to "point out the differences between the two."

He told CNN: "There is no clear line on the part of the Nazis to say what is degenerate and what is acceptable. But all objects which were not naturalistic or realistic were not okay for the Nazis."

The museum believes the sculptures were saved by Erhard Oewerdieck, a tax accountant better known for his efforts in assisting Jewish citizens escape the Third Reich.

Wemhoff said it's likely the works were hidden in his fourth floor office building in Kings Street, opposite the Town Hall. But the building was destroyed by a fire during a bombing raid.

"It's an unbelievable find. That they survived both the Nazis and the bombs" said Wemhoff. "Now they show many signs and relics of the war, they look like antique objects."