Solution:

• The Neyyar River is a river of south-western India in the Western Ghats. It flows from the Agastya Mala (also known as Agastyarkoodam) hills in of Thiruvananthapuram District of Kerala state.
• The river passes through Neyyattinkara taluk into the Lakshadweep Sea near Poovar. It has a total length of 56 km.
• Thiruvananthapuram district, is situated on the banks of the river, is named after this river.
• The river flows through the Neyyar wildlife sanctuary and into the Neyyar resorvoir.