A Federation starbase whose medical facilities were the only hope for a critically ill boy when Data suddenly hijacked the Enterprise-D and took the ship elsewhere.
Starbase 416 is a Starfleet installation mentioned in the Next Generation episode Brothers. It is the nearest base with the equipment needed to treat a rare parasitic infection.
In 2367 young Willie Potts is tricked by his brother Jake into eating a contaminated cove palm fruit during shore leave on Ogus II. Doctor Crusher can only keep him alive in quarantine, and the Enterprise-D sets course for Starbase 416 at speed.
The journey is interrupted when Data, answering a homing signal from his creator Noonien Soong, seizes control of the ship and diverts it. Only after Data is recovered and releases the computer does the Enterprise resume its course, reaching the starbase in time for the boy to be treated.