It is a natural fortress guarding the narrowest strip of coastal plain, and historically there was a wall, gate and caravanserai for travelers to be channeled through for a price (this is now entirely vanished). 18th-Century travelers commented on the many languages of graffiti on walls (French, Polish, Arabic) as evidence of it's heavy traffic.
On weekends many Azeris come seeking good fortune, a child, or the answer to their problems using a mixture of prayer, sacrifice, chanting and kissing the rocks.
"Take three small stones to the top, sip thrice from a cup of holy water, kiss the sacred rock three times, then incant your wish... guess how many times." (Lonely Planet)
The ridge-top parking lot is a steep 10 minute drive from the Quba highway where a new mosque/Namazkah (prayer room) has been built (turn off is 3km north near an old tea shop). From the parking lot it is a 15 minute walk to top via precarious and wobbly metal staircases. Alternatively, it's around a 90 min walk up (steep and sweaty) from the highway.
The parking lot also harbors a well of holy water and a "sacrifice point" (sheep slaughtering area). The Imams also share in the rituals.
Source: Lonely Planet Georgia, Armenia and Azerbaijan, 3rd Edition
Mark Elliot's Azerbaijan 4th Edition