Uthirakosamangai temple, Ramanathapuram, TN - famous for emerald Nataraja idol

Mangalanatha swamy temple, Ramanathapuram, TN, you tube

Mangalanatha swamy temple, Ramanathapuram, TN en.wikipedia.org

Nataraja idol made of emerald, Maragathanathar temple, TN,Pinrest com

Uthirakosamangai Mangalanatha swamy temple, dedicated to  God Shaiva, 15 km from Ramanathapuram town in the Ramanathapuram district of Tamil Nadu is an old one which is believed to have been  built at various times  by the Pandya kings, Achutappa Nayak (1529–1542 CE.), Muthuveerappar and other rulers of Ramanthapuram  Sethupathy Dynasty. The stone carved sculptures like Yali (lion like) are  made with care and dedication,  hence they look impressive.  This temple is older than 9th century. 

Among the several shrines, Mangalanathar, Mangalambigai and Natarajar are prominent. An interesting feature of this temple is the 1.8 meter tall maragatha Nataraja idol made from a single emerald stone. It is kept in the safe vault as it it is priceless. It is anointed with sandal paste round the year except on Tiruvathidirai festival day when special worship is done.  No percussion instruments are allowed during puja near the maragatha idol as the sound vibrations might damage the precious idol.The Raja gopuram - tower is a 7 tier structure and a hall near the sanctum has 1000 lingams. The temple has many shrines as one will find in the Shivalayas.  The lingams made of Padigam (spatika) in the front hall are anointed with cooked rice every afternoon during puja. This temple is a rare  one where thazhambu  (screw-pine flower) is still used for worship contrary to the tradition. Manickavasagar, the 9th century Tamil saivite saint poet glorified  Mangalanathar and the temple in his hyms in Thiruvasakam, compiled as the Eighth Tirumurai. Arunagirinathar, a famous 15th-century Tamil poet composed Tamil hymns glorifying Murugan in the temple. It was here God Muruga was bestowed with  Airavata (white elephant)  by celestial god  Indra.

The name Uthara Kosa Mangai  where the temple is located, is derived from  "Mann Mundhiyo Mangai Mundhiyo" It means " Which one came first- mud (mann) or Mangai (the goddess of the temple)?".The legend has it it was here God Shiva revealed the secrets of the Vedas to Parvati. Uthiram meaning upadesam,  kosam  implies secrets and  Mangai refers to Parvati.

The temple tank is called Agni thertham  as the legend says: once responding to 1000 rishis' (sages) penance,  God Shiva told them that  he would appear here later as a ball of fire after responding to penance done by Mandothiri, Langa king Ravana's mother. Appearing before Mandothiri in Langa as a small kid, king Ravana, struck by the child's beauty lifted him. At that time a fire ball  came out of the Agni Theertham at this temple and  the sages thought Ravana and the god were at war. Out of 1000 sages, 999 killed themselves by getting into the fire and the sage who remained alive saved the Vedic scriptures. Shiva pleased with the  sage  for his timely action and  appeared as Sahasralingam (thousand lingams); one for himself and   999  for the sages who killed themselves here. The sage who saved the Vedas is believed to have taken rebirth as Manickavasgar in his later birth.  

The distinctive temple tradition here is as part of the worship protocol  the  priests  read the Veda texts  to the accompaniment of  nagaswaram (wind instrument) music. Once it is over, devotees who attend the prayer/puja prostrate toward  the main deity   in front of the temple mast or Dwajsthambam. Among the several festivals held here Pathunal Siva Uthsavam during Aaani (July–August), Annabishekam during Aipasi (October–November), Tiruvathidirai during Margazhi (December–January) and Sivarathri during Masi (February–March). The Tiruvathidirai festival in December are celebrated with pomp and devotion  by the countless devotees. The temple is being managed by HR & CE, a govt. organization which is muddled with corruption, land-grabbing financial irregularities, etc. 
 https://en.wikipedia.org/wiki/Uthirakosamangai

https://www.trawell.in/tamilnadu/rameshwaram/uthirakosamangai