T'rthrium was a large sub-dimension of Universe BR-45327/A before its destruction. Home to the Chalidrytes, Agnaren, and a host of other alien species, T'rthrium's beauty was unparalleled by any other known sub-dimension of its home universe.
To be added.
T'rthrium was much like a ceilingless cave; large stalagmites ascended from a dark, bottomless pit into the sky above, which was a pure and brilliant shining white that maintained its luminous glow constantly, despite the complete and utter lack of a sun. Atop the flattened heads of most stalagmites were built alien settlements, large and small. Waterfalls flowed from the cavernous walls of T'rthrium and either fed rivers and lakes on nearby stalagmite platforms or simply gushed into the darkness below. Many of the stalagmites were host to fields of luscious green vegetation and flora.
(To be expanded.)