Yadalla was a planetary star system in Sector 2158 of the Beta Quadrant. A planet in this system, Yadalla Prime, was home to ancient Romulan ruins. This system, at the edge of its sector, was near the Romulan Neutral Zone in the mid-24th century.
In 2399, the location of Yadalla was labeled in a Federation star chart that was in Fleet Admiral Kirsten Clancy's office at Starfleet Headquarters. This system was in or near to space claimed by the Romulan Free State. (PIC: "Maps and Legends")