Kalasthambadi BO is the primary post office registered under PIN code 606805 in Tiruvannamalai, Tamil Nadu. This code sits within the Southern Postal Region, with 4 offices operating under it.
| Post office | Type | Full name |
|---|---|---|
| Kalasthambadi BO | BO | Branch Post Office |
| Mallavadi BO | BO | Branch Post Office |
| Turinjapuram SO | SO | Sub Post Office |
| Kolakkaravadi BO | BO | Branch Post Office |
