Officials from Berlin's Pergamon Museum announced plans Wednesday to dismantle and remove much of its famed Market Gate of Miletus over the next year and a half and to spend the next 10 years restoring it.

The towering Roman gate, built around 120 A.D. as the entrance to the market square in the Aegean coastal city of Miletus in what is now Turkey, is one of the museum's chief attractions. But metal supports built decades ago are sagging dangerously.

In the next three weeks, workers will cut a hole in the 75-year-old museum's southern exterior wall. Through it, they will pass 58 of the gate's marble blocks — weighing about 110 tons — to load them onto flatbed trucks and take them to an offsite facility for restoration.

The entire project is expected to take about 10 years and cost about $60 million, according to Gisela Holan, who oversees reconstruction work on the Pergamon and the four other museums that collectively make up Berlin's Museum Island.

The museum plans to put up a transparent wall that will contain dust and noise but let visitors continue to view the gate. Peter-Klaus Schuster, city museum director, said the unique setup will help make the Pergamon an "academy of restoration work."

The gate's ruins were recovered by German archeologists and brought to Berlin in the early 1900s.