The Ranger Grotto was the secret base of the Mon Calamari Rangers during the Second Imperial Civil War and the Massacre of New Coral City. The grotto was located deep within the depths of the oceans of Dac, hidden from the scanners of the Imperials loyal to Darth Krayt's Galactic Empire. The base harbored the Rangers and their leader Tanquar as they ran hit-and-run attacks on the Imperials who were systematically exterminating the Mon Calamari. The grotto was also home to Imperial Knight Treis Sinde, who aided and advised the Rangers in their guerrilla war against the Empire. The Rangers' attack craft, the Krakana, were docked in the grotto, anchored to the ceiling of the base. The base was only a few kilometers away from the Soheras Trench.
Following a failed attempt to capture an Acklay-class mobile fortress, the Mon Calamari Rangers brought a group of rescued refugees back to their grotto. However, Sinde would not allow the refugees to stay, as they had no way to feed them, and an increased presence at the base would risk the possibility of the Imperials finding them. Tanquar argued with Sinde over the decision, but the refugees agreed with the Imperial Knight's assessment, as they did not want to danger their protectors.