(4) Kerala -Tamil Nadu Explanation: The Agasthyamalai Biosphere Reserve (ABR) was established in 2001 and includes 3,500.36 square km of which 1828 km2 is in Kerala and 1672.36 km2 is in Tamil Nadu. It straddles the border of Kollam and Thiruvananthapuram Districts in Kerala and Tirunelveli and Kanyakumari Districts in Tamil Nadu, South India at the southern end of the Western Ghats.