Altostratus Aeries of the Hawk-Men: Battleflights of the Blessed. 'Nuff Said.
The Ark of the Sun: The Myth-Sonic Space Ark of the demigod Sun Ra, trapped in a null-sound field by his ancient enemy the Overseer. Audio technicians conjecture that the proper quadraphonic array might be used to free the Ark.
Citadel Carcosa: A floating citadel built from black and green stone mined in unknown quarries, inhabited by mad scientists, demonologists, cryo-lich warlocks and vorvons. Their society, such as it is, centers on the pursuit of obscure ingredients needed for their weird rites, eldritch wizardries and controversial child-rearing practices. Also, they are cannibals (with apologies to Geoffrey McKenna).
The Midas Fleet and the Second Golden Planet: A legendary planetoid made entirely of gold, orbited by the remains of the Midas Fleet who sought to exploit it. A vast, unguarded treasure floating in space, but sages warn that none may touch planet or ships without also turning to gold. (swiped from Ryan North's Dinosaur Comics, particularly the alt-text.)
One of the galaxy's most notorious prisons, carved from the sentient skull of a Greater Void Dragon, your basic hive of scum, villainy, weed-men, boar-tuskers and brain bankers. Towed into Vanth orbit by slime pirates, who have long since abandoned their Petri Saucers but are said still to rove the high atmosphere (vide Scott Driver's Thool & Wilderlands).