Context: 

The Tamil Nadu Department of Archaeology has declared five ‘menhir’ (single stone) and megalithic burial sites at Kodumanal in Erode district as protected monuments.

Findings at Kodumanal site:

• Potsherds containing names inscribed in Tamil-Brahmi script were found in a large number, apart from Roman silver coins, precious stones and quartz. 
• These findings showed that an industrial and trade centre had existed here about 2,300 years ago.

About Menhir:

• Menhirs are the megalithic pillars having small or gigantic height planted vertically in the ground.
• They are commemorative pillars set up at or near a burial site. 
• Menhirs are known by various names like Nilskal, Nintikal, Anekallu, Rakkasakal, Garbinikal and so on in South India.
• They are mentioned in ancient Tamil literature as nadukal.

About Megaliths:

• In prehistoric art, a megalith is a large, often undressed stone that has been used in the construction of various types of Neolithic, Chalcolithic or Bronze Age monuments, during the period 4500-1000 BCE. 
• Also known as petroforms, these monuments can consist of just one stone (Menhir), most megalithic monuments consist of a number of stones, which are fitted together without the use of mortar or cement.
• The megalithic monuments of peninsular India, believed to have been erected in the Iron Age (1500 BC – 200 AD).
• Though megalithic sites are found all across India,  they are concentrated mostly in peninsular India. 

News Source: The Hindu