Purchase a ticket to see a game at Mochtar Stadium. If there's nothing scheduled while you're in the area, you might like to check if the stadium offers a guided tour of the grounds.
You'll quickly figure out why this sporting facility is on the sightseeing list of many visitors to Pemalang. When you've paid the entry fee, wander inside and make a day of it. Looking for other things to keep you entertained close to Mochtar Stadium? Head on over to Alun Alun Kota Pemalang, Widuri Beach and Widuri Water Park.