Kota Kuala Kedah is the old fort at the mouth of the Kedah River, also known as Kota Kuala Bahang. It was built to defend Kedah from attacks arriving by sea, and its position still makes sense when you stand near the river mouth and look toward the strait.
The area is now as much fishing village as historic site, with seafood restaurants around the old fort. It makes an easy trip from Alor Setar, especially if you want to pair a dose of Kedah history with lunch by the water.