One should visit in his/her lifetime the eight powerful temples of Lord Vishnu representing the energies of the eight letters of ‘Om Namo Narayana’, at:
1. Sri Venkateswara Samy (Sri Balaji) Temple Tirupati, Andhra Pradesh
2. Sri Ranganatha Samy Temple, Srirangam, Tamilnadu
3. Sri Bhoovaragaswamy Temple,Sri Mushnam, Tamilnadu
4. Sri Vanamamalai Perumal, Nanguneri, Tamilnadu,
5. Sri Muktinath Temple, Saligramam, Nepal
6. Sri Badri Narayana Perumal, Badrinath, Uttar Pradesh
7. Sri Devaraja Perumal Temple, NaimisharaNyam,Uttar Pradesh and
8. Sri Varahasamy Temple, Pushkar, Rajasthan
Each of these 8 Temples has Self Manifested Idol (Swayambu) of Lord Vishnu.
Therefore, these temples are called Vyaktha Kshetras,that is where Lord Vishnu makes Himself available as Idol and thus becomes Describable. Also called Astakshara Temples as they represent the eight letters of Vishnu’s Sacred Name,
Om Namo Narayanaya.
These temples grant liberation to those who visit as per Sri Ramanujacharya’s scriptures. Like the 12 Jyotirlingas these eight are Astakshara Swayam Vyakta Kshetras of Lord Maha Vishnu. This information can be extracted from the sloka given below by the Acharya:
Srirangam Venkatadrischa SrimushNam Totaparvatam
Salagramam Pushkaramcha NaranarayaNAshramam
Naimisham Cheti ME SthananyasoU Mukthi PradhAnivai
YetusvashtAksharaIkAka: VarNamUrthir VasAmyaham
TishtAmi KrishNa KshEtrE puNya SapthakOgatha:
AshtAksharasya Mantrasya SarvAkshara Maya SadA
In this verse Acharya points out that the eight Swayam Vyakta Kshetrams of Srirangam, Tirupathi, SrimushNam, Vanamamalai, Salagramam,Badri, NaimisharaNyam,and Pushkar grant liberation to those who visit the place. The Lord as the Archa Murthy at each of these Kshetrams signifies one Aksharam of His Ashtakshara Mantram.