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Wikipedia: Temple of Olympian Zeus, Athens
Wikipedia provides historical information and images of the ancient Temple of Olympian Zeus in Athens, Greece.
Other
Agora Temples: The Temple of Zeus Phratrios and Athena Phratria
A brief account of a temple built at the foot of the agora in Athens. Describes the altar inside and has links to photos of an inscription.
Other
Porter Gaud: Greek Architecture: The Parthenon
A set of notes on one of the most famous temples in the ancient world. The author discusses the building of the temple along with a detailed description and an analysis of the various statues.