Doric order
One of the three orders or organisational systems of Ancient Greek or classical architecture characterised by columns which stood on the flat pavement of a temple without a base, their vertical shafts fluted with parallel concave grooves topped by a smooth capital that flared from the column to meet a square abacus at the intersection with the horizontal beam that they carried.
Source: https://en.wikipedia.org/wiki/Glossary_of_architecture