Kalandra is a sector in the Alpha Quadrant.
In 2374, during the Dominion War, the Dominion seized the Kalandra sector. The sector, along with the captured Betazed, allowed them to move into a position where they could attack Vulcan. (DS9 episode: "The Reckoning")
In 2375, Cardassian transmissions decoded by Elim Garak suggested the Kalandra was vulnerable to attack. The Starfleet 7th Fleet, including the USS Destiny, was to launch an offensive on Kalandra. (DS9 episode: "Afterimage")
The Kalandra sector was later retaken by Starfleet. Later in 2375, the USS Defiant and seven other Federation starships were waiting for the IKS Ch'Tang and Martok's other ships after the Klingon cavalry raid into Dominion space. (DS9 episode: "Once More Unto the Breach")