<human>:  When did the Greeks start building columns?
<bot>: Columns were first used in the Parthenon, which was built in 447 BC. The Parthenon was the largest temple in Ancient Greece, and was dedicated to the goddess Athena. The Parthenon was made from marble, and the columns were made from a special type of stone called Pentelic marble. The Greeks also used the Doric and Ionic styles of column.