Jeeva Samadhi or Adhishtanam or Brindavanam is the tomb of a Hindu Spiritual Guru or a saint. It is believed that the saint's life force still exists in the tomb and prayers are offered to it.
"Brindavanam" is the term used for Vaishanavaite saints and Adishtanam for the rest of them. It is called as Jeeva Samadhi in Tamil Nadu, mainly with reference to Siddhars. There are hundreds of them spread all over India. In case of shaivaite saints, a Shiva linga is placed over the tomb and for vaishanavaite saints, the sacred Tulsi tree is planted.
In this concept, by spiritual practices, life is not allowed to go out of the body. The seed cells in the body never get damaged. Such a person stops the functions of the body after completion of his or her mission by his or her own will. Gnani will fix his or her mind with the Almighty and stop functioning. The body is then buried. That body will never decay whether it is thousand or ten thousand years, because the magnetic force in the body itself acts as a life force in the body. As "unseen masters" or "invisible helpers" they guide the human race to wisdom.
It is believed that this force remains forever and the time limit for the Samadhi status depends upon the saint's bio-magnetic strength, which may vary in terms of hundreds of years. Until then, the soul in samadhi stage will continue to bless the devotees. The place around such Jeeva Samadhi has very high spiritual magnetic force. It can be sensed by the gnana aspirant. If these places are maintained properly, they become energy banks supplying the needful.