Thandalam lies between Sholingar and Tiruttani
, off the Arakkonam
road. It derived its name from the Tamil phrase 'than thalam', meaning a cool place.
The place is famous for the Adi Kesava Perumal Temple. Sage Agastya is said to have stayed here and worshipped Lord Shiva and so the Lord is also known as Agastheeswar. A temple for Lord Ganesh is on top of a small hillock.
Vellore is the nearest railway station.