From Halopedia, the Halo wiki
New Miskolc was a former city on the Inner Colony world of Reach.
During Operation: WOLFE in 2559, a flight of Seraphs flying from the direction of the city began to chase the UNSC Special Delivery as it inserted into Reach. Major Eznik Van Houte theorized that the city might have contained UNSC administration facilities at some point.
The city was likely named after the Hungarian city of Miskolc.