State Highway 21 runs from
Chalakudi on the
National Highway 47 up to
Anamalai, on the
Kerala–
Tamil Nadu border, in
Thrissur District. State Highway 21 starts at Chalakudi and runs eastwards touching Athirampally, Vazhachal, Peringalkuthu and through the approach road to Sholayar Power House, before ending at Anamalai. State Highway 21 has a total length of 86 km.
