Original location of the altar of Zeus at Pergamum. The structure around the altar dedicated to Zeus is actually not a temple but an open-air altar. The tree in the centre marks the location of the altar, but the structure which surrounded it was relocated to the Pergamum Museum in Berlin, Germany to prevent it from being destroyed by locals during excavation between 1878 and 1886. Strangely, it is only mentioned by Ampelius, who described it as “Pergamon [sic.] altar forty feet tall with very large marble sculpture, which contains a Battle of the Giants” (Lib. Mem. 8.14 [Graves]). This has been identified by some commentators as the “throne of Satan” in the message to the church in Pergamum. However, other centers like Olympia, Greece also had open-air altars to Zeus.