Starbase 257
Starbase 257 was a Federation  starbase that was in service with Starfleet in the late 24th century. The outpost was located in the Alpha Quadrant.

While within its defense perimeter, ships had to remain at one-half impulse until they cleared the outer markers.

In 2374, the starbase was attacked by an attack wing of Jem'Hadar fighters, shortly after the runabout  had left the station en route to Ferenginar. ()

In 2399, the location of Starbase 257 labeled on a Federation star chart in Fleet Admiral Kirsten Clancy's office at Starfleet Headquarters. The outpost was in or near to Federation space. ()

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bg:Звездна база 257
cs:Hvězdná základna 257
de:Sternenbasis 257
nl:Sterrenbasis 257
0257, Starbase