Rajathan

The Rajathans were a species once native to the planet Rajatha Prime. Their civilization died out in approximately the 4th century.
 * Based on Jean-Luc Picard's claim that no person had walked the halls of Rajathan ruins in two millennia prior to 2368.

The Rajathan civilization was a pre-industrial society. They built larger cities with monumental structures. There constructs included ziggurats which featured ceremonial entrances to heaven and the underworld, as the Rajathans were "pathologically non-judegemental" they gave both entrances equal status. Inside these entrances were chambers containing sarcophaguses and other decorative items. (TNG comic: Captain's Pleasure)
 * On their level of architecture and art the Rajathan civilization would seem to be roughly comparable to the Maya of Earth.