View looking east down on the altar of the second temple of Hera. Behind, upper left, are the remains of a larger, earlier altar.
According to Wikipedia: The second Temple of Hera was built around 460–450 BC, just north of the first Hera Temple. It was once mistakenly thought to be dedicated to Poseidon. The columns do not have the typical 20 flutes on each column, but have 24 flutes. The Temple of Hera II also has a wider column size and smaller intervals between columns. The temple was also used to worship Zeus and another deity, whose identity is unknown.
The sign at the site of Paestum says that it was a temple to Apollo!