Using Erwin Stumm's Silurian and Devonian Corals of the Falls of the Ohio from 1964 this coral appears to be an Emmonsia tuberosa (originally described by Rominger in 1876 as a Favosites tuberosus). Its pentagonal or hexagonal corallites seem to be about 3 mm wide. There is also evidence of a smaller number of trigonal or tetragonal corallites. Found in Jeffersonville Limestone from central Jefferson County, Louisville, Kentucky.
With the white-gray rock and the straight lines almost parallel it reminds me of an art deco look from the 1920s and 1930s. The hexgonal pillars next to each other somewhat reminds me of the Giant's Causeway in Northern Ireland.