Holy waters: (pushkarini)
The pushkarini (temple Tank) here is known as 'Ahoratra pushkarini" , meaning that bathing is specially permissible here both during day and night. Normally according to sastras, bathing in holy waters is not permitted during nights. But nowadays bathing is permitted here, only when the temple is kept open for dharsan.
Once a learned brahmin by name Devasarma was overcome by passion and had a forceful union with the daughter of Jaimini rishi. On her tearful complaint to her father, the rishi cursed him to become a krauncha bird.
It-was then the sinner repented and begging pardon, requested the stage not to impose the curse. The sage relented and advised that while he could not withdraw the curse already pronounced, as a bird he might live in the branch of a tree overlooking the holy pushkarini at this place. A cyclone would blow and break the branch of the tree, which would, along with the bird, fall into the holy waters. Due to the bird's contact with the holy waters, he will be released from the curse and regained his original form. Not only that, he was also escorted to Sri Vaikuntam in a divine chariot. Then the messengers of Varuna stopped him and demanded justification for going to Vaikuntam, since he had committed a further sin by dipping in the holy waters during the night, which is forbidden by the sastras. At this, the messenger from Vaikuntam intervened and clarified that this was an exception and bathing was specially permitted in the pushkarini at this holy place, both during day and night and the pushkarini at this holy place, both during day and night and the pushkarini was herefore named as Ahoratra pushkarini meaning "Day and Night Holy Tank". Thus saying, th Lord's messengers took the brahmin to Sri Vaikuntam. Anyone who bathes in the pushkarini acquires a lot of merit ( punya).
There are other holy tanks as well, outside the temple. Sarnga tank to the south-west of the temple is consiered holier than Dhanushkodi. Surya tank to the west of the temple has an interesting legend. Siva once plucked one of the heads of Brahma (who had five heads earlier) and to get rid of the sin, he bathed in the holy waters of Ahoratra Pushkarini and is still doing penance here. Since Surya(Sun) repaired this tank, it is called Surya tank.
In the north-east of the temple is indra tirtha (tank), so named because Indra washed off his sin of molesting Ahalya, by bathing in these holy waters. To the south of this is Brahma tirtha, so named because Brahma bathed in this tank and did penance, because of which he became what he was (Brahma).
All these tanks outside the temple do not exist now. Either they have become completely dry or they could not be located.
To the south of the temple run three holy rivers, even now:-
1.Dakshina Ganga (ganga of the south), now named as Nattaru
2.Dakshina Yamuna, now known as Arasalar.
3.Dakshina Godavari, now known as Kirtiman river.
Other holy waters:
Sarnga Tirtham, Surya Tirtham, Indra Tirtham and Brahma Tirtham are situated outside the temple according to puranas. These are now dry and not fit for bathing.