Poly-Chlorinated Biphenyl Beach?
No, PCB Beach isn't named after a nasty industrial chemical: the original name was Pantai Cinta Berahi or the "Passionate Love Beach". Alas, this was a little too daring for State Government, and now the official name is Pantai Cahaya Bulan, "Moonlight Beach".
Go to the day and night markets. Have Nasi Kerabu for lunch at the day market and Ayam Percik at the night market, or get whatever else strikes your fancy.
Walk around the downtown area.
Bicycle around Pengkalan Chepa area airport, see old WW2 British pillboxes near beach at Pantai Sabak. For history buffs only but no beach anymore due to erosion.
Go to the beach, either PCB Beach or Irama Beach Beach of Melody. PCB Beach has batik shops, one of which is Citra Batik about 500m from the beach. Also eat fried seafood at PCB Beach or Irama Beach with coconut water.
Beautiful beaches at Bachok - Pantai Perkasa, Pantai Sungai Dua, Pantai Kandis.