National Highway 66 connects the Union Territory of
Pondicherry with
Krishnagiri, at the junction of national highways
7 and
46, in
Tamil Nadu. National Highway 66 starts at Pondy and runs north-west up to
Tindivanam, the distance traveled being 39 km. It then turns westwards and passes past Gingee and
Thiruvannamalai, turns north-west and then beyond
Mattur to eventually terminate at Krishnagiri. National Highway 66 is 10 km long in Pondicherry while the rest of its 234 km is in Tamil Nadu.
