D'k tahg Valley was a region on Qo'noS. It was also a popular shooting location for Klingon films and television shows and, as such, it was home to much of the Klingon entertainment industry. It was largely considered to be the Klingon Empire equivalent of Hollywood in 20th century and 21st century Earth. However, it wasn't, by itself, a constituency important enough to be represented in the Klingon High Council on its own. (Star Trek: False Vacuum)