Final answer:
The Great Altar of Zeus at Pergamos is primarily made of marble and features a notable frieze depicting the Gigantomachy. It dates back to around 175 BCE and was commissioned by King Eumenes II.
Step-by-step explanation:
The Pergamos Altar was a monumental construction built during the reign of the Ancient Greek King Eumenes II in the first half of the 2nd century BC on one of the terraces of the acropolis of Pergamos in Asia Minor.
The Great Altar of Zeus at Pergamos, a notable example of Hellenistic architecture and sculpture, is primarily made of marble. Built circa 175 BCE under the commission of King Eumenes II, this eminent structure features a U-shaped design and is celebrated for its intricate frieze depicting the Gigantomachy, which extends around the base of the altar for an impressive 370 feet. Originating from present-day Turkey, the altar now resides in Germany and serves as a testament to architectural and artistic skills of the Hellenistic period.