Ahobhilam, also known as Ahobalam is located in the Allagadda mandal of Kurnool district in Andhra Pradesh, India. It is located at a distance of 40 km from Nandyal and about 150 km from Kurnool, the district headquarters. There are two temple houses, lower Ahobilam and upper Ahobilam.
It is a major pilgrimage site in South India, is one of the 108 Vaishnava Divyadesams and known in Tamil as Thiru Singavel Kundram. According to the legend, this is where Lord Narasimha blessed Prahlada and killed the demon Hiranyakashipu.
Aho is an exclamation word. Bhilam (bhilam means cave). It is equivalent of 'oh the mighty cave' and thus aho-bhilam of lord Narasimha swamy. One famous slokam that explains this is:
Aho veeryam! aho shouryam! aho baahu parakrama!
Naarasimham param deivam aho bhilam! aho balam!
Oh! what a great valour he has! oh his great gallantry! oh those great powerful shoulders of the greatest of the Gods Lord Narasimha, and what a the mighty cave it is! and what a mighty divine strength He has!

The nine planets that define the human fates are believed to have worshipped these nine Lord Narasimhas to get relief from Rakshashas (demons) and curses of sages for their actions.
The hereditary powers of the temple rest with the Pontiff HH Azhagiyasingar of Ahobila Mutt.
The Nallamala hills are personified as Adisesha with his head at Tirumala, middle at Ahobilam and the tail at Srisailam.
Legend
According to legends it is believed that when the Devas saw the manifestation of Lord Vishnu as half-lion, half-man, they shouted "Ahobala" (great strength) as well as "Ahobila" (great cave in which the current sanctum is). Hence, this place could be called either "Ahobalam" or "Ahobilam". The mention of this place is present in Brahmanda Purana. The place where Lord Narayana appeared from the stone pillar to kill Hiranyakashipa can be seen in this place. The name of this pillar is Ugra Sthambha.
The legend says Lord Narasimha, after slaying Hiranyakasipa was roaming around the forest hills of Ahobilam making fearsome laughs and settling at nine places to bless the devotees. Here are the Nava Narasimha temples. Another legend describes when Lord Garuda did penance to see Lord Vishnu in Lord Narasimha form. Thereafter, Lord Narasimha took nine different forms in this hill.

Narasimha Prapatti
MATA NARASIMHA, PITA NARASIMHA
BRATHA NARASIMHA, SAKHA NARASIMHA
VIDYAA NARASIMHA, DRAVINAM NARASIMHA
SWAMI NARASIMHA, SAKALAM NARASIMHA
ITHO NARASIMHA, PARATHO NARASIMHA
YATHO YATHO YAHIHI, TATHO NARASIMHA
NARASIMHA DEVAATH PARO NA KASCHIT
TASMAAN NARASIMHA SHARANAM PRAPADYE
Translation
Mother is Narasimha; Father is Narasimha
Brother is Narasimha; Friend is Narasimha
Knowledge is Narasimha; Wealth is Narasimha
My Lord is Narasimha; Everything is Narasimha.
Narasimha is in this world, Narasimha is everywhere (Omnipresent)
Wherever I go, there is Narasimha
Narasimha is the Supreme Lord, there is none other than HIM
So, I humbly seek refuge in you, Shri Narasimha
Happy News :
The replica of all Nava-Narasimhas will be installed in Sri LaxmiNarasimha temple, HBR layout Bangalore, so that devotees can have their Darshan & blessings in one place
