When is the last time we see the Gamma Quadrant in Star Trek: Deep Space Nine? I recall it felt like it was quite far from the end of the series but I cannot recall which episode was the last and what the content of that episode was (i.e. the reason to visit).
The last episode featuring an adventure in the Gamma Quadrant is DS9: Children of Time toward the end of season 5.
Captain's log, stardate 50814.2. The Defiant is returning to Deep Space 9 after a week-long reconnaissance mission in the Gamma Quadrant.
We don't then see the Gamma Quadrant side of the wormhole until the show's finale episode, DS9: What You Leave Behind when Odo returns to his people at the end of season 7.