Azhagar Koil is a very popular destination in Madurai. The shrine for Azhagar (Lord Vishnu), Palaimuthir Solai (Lord Muruga) are well known.
If you climb the nearby hill, there is a small spring located on the top called Noopura Ganga. The water of this eternal spring tastes so sweet. There is also a small temple for Goddess Rakkayi nearby. The TamilNadu government runs a small herbal garden here.
But what most people arent aware is the Samadhi of Rama Deva Siddhar which is a 7-8 kms trek from this place. There is a small Shiva Linga at the samadhi but nothing else. Rama Deva was one of the 18 Rishis or Siddhars who were well versed in ancient medicine,alchemy and other sciences.
There is another group of people who believe that the Samadhi of Rama Deva rishi is that of the Lord Narasimha shrine located just behind the main deity in Azhagar Koil ( seen in the image below). There seems to be an older shrine for Narasimha in the temple and this shrine which stands out seperately in an elevated platform doesnt seem to be inline with the general temple structure.