Known Space
Within the Tales of Known Space, the epithet "Known Space" refers to a relatively small region in the Milky Way galaxy, one centered on Earth. In the future that the series depicts, spanning roughly the third millennium, humans have explored this region and colonized many of its worlds. Contact has been made with other species, such as the two-headed Pierson's Puppeteers and the aggressive felinoid Kzinti. Stories in the Known Space series include events and places outside of the region called "Known Space" such as the Ringworld, the Pierson's Puppeteers' Fleet of Worlds and the Pak homeworld.