Nava Tirupathi

https://en.wikipedia.org/wiki/Nava_Tirupathi

Each of the nine temples represent one of the nine grahas of navagrahas

Although the number of temples are nine, it constitutes only eight divyadesams with two temples called Irratai tirupathi combinedly considered as just one divyadesam.

http://prtraveller.blogspot.com/2007/07/108-divya-desam-nava-tirupathi.html
http://www.tamilbrahmins.com/pilgrimage/2969-nava-thirupathi-tour-3.html

No	Temple	Perumal	Thayar	Distance from SriVaigundam	Temple Open Morning	Temple Open Evening
1	Srivaikundam Sun – Suriyan	Vaikundanathan Kallapiran	Vaikundanaayani Sooranathanayagi	-	8.00 – 12.00	5.00 – 8.00
2	Srivaragunamangai Natham Chandran	Vijayasanar Emmiderkadivan	Varagunamangai Varagunavalli	2 KM	9.00 – 12.00	1.00 – 6.00
3	Thiruppuliyangudi Puthan	Boomipaalagar Kaaichinaventhar	Nilamagal Pulingudivalli	3 KM	9.00 – 12.00	1.00 – 6.00
4	Erattai Thirupathi Raagu	Srinivasan Thevarpiran	Alamelumangai	10 KM	8.00 – 12.00	1.00 – 5.00
5	Erattai Thirupathi Keethu	Aravinason Chenthamarai Kannan	Karunthdankanni	10 KM	8.00 – 12.00	1.00 – 5.00
6	Thirukuzhanthai Perungulam Sani	Venkadavannan Maayakoothar	Kamalavathi Kulanthivalli	12 KM	8.00 – 12.00	5.00 – 8.00
7	Thenthiruperai Sukran	Maharenedun Kuzhaikaathar Niharilmukil vannan	Kuzhaikaathu valli Thiruperal Nachiyar	10 KM	8.00 – 12.00	5.00 – 8.00
8	Thirukkolloor Sevvai	Vaithananidhi Nichopavithan	Kumuthavalli Kollor Valli	8 KM	8.00 – 12.00	5.00 – 8.00
9	Azhwarthirunagari Viyazhan - Guru	Aadinathan Polinthunintrapiran	Aadinatha Nayagi	5 KM	8.00 – 12.00	5.00 – 8.00

Tube
https://www.youtube.com/results?search_query=Nava+Tirupathi

Perumal

https://en.wikipedia.org/wiki/Thirumal
http://divyadesamperumal.blogspot.com/
https://www.youtube.com/user/perumal108/videos

Desh

http://www.divyadesh.com/

Kataksham

https://divyakataksham.wordpress.com/

Koyil

http://koyil.org/

Garland

http://immersedimmersed.blogspot.com/search/label/Andal

Three in One

Sage Parasara sprayed the nectar he obtained from the milk ocean in the Manimutha River, built a hermitage on the river bank and was performing penance.  Three demons

1. Thanjakan, 
2. Thandakan and 
3. Tharasura with their deathless boon granted by Lord Shiva began to harass the sage and others performing penance with him.  

The sage advised them to shed their demon traits and reform themselves.  They turned a deaf year. The sage appealed to Lord Shiva for protection.  Shiva sent Kalidevi to destroy them.  But they drank the nectar mixed river water and came back alive to continue their atrocities.  Sage approached Lord Vishnu.

1. Mahavishnu took the Narasimha form and defeated Thanjaka who took the elephant form.  Lord placed the demon on His lap to kill him when he gained wisdom and shed his cruel traits.  He also begged the Lord to stay in the place and bless all.  He also begged that the place should be named after him.  His boon granted, the place came to be known as Thanjamapuri. 
2. Seeing the defeat of Thanjaka, Thandakan hid himself under the earth.  Lord became a Varaha, entered the hiding and killed the demon.  
3. Tharaka was killed by Kali.  

After the destruction of the three demons, Lord appeared before Sage Parasara as Neelamega Perumal.  Lord is gracing this place in three names in three separate temples.

Lord Vishnu who destroyed the demons graces in three separate temples as 

1. Neelamegar, 
2. Manikundra Perumal and 
3. Veera Narasimha in three forms. 

Saints Boodhathazhwar and Tirumangai Azhwar had sung the glory of the three Perumals together in their hymns. The three temples form a single Divya Desa.

https://www.google.com/search?site=imghp&tbm=isch&source=hp&biw=1280&bih=643&q=Neelamega+Manikanda+Perumal+and+Veera+Narasimha