This is one of the seven Shaktipeeth described in Kalika Purana.
Location of Vasistha temple:
Towards the east of the city Guwahati>Basistha temple
Near three rivulets Sandhya, Lalitha and Kantha [Map].
The Vasistha temple is locally called as Basistha / Basistho. It is located on a hill by name Sandhyachal with lot of Natural beauty. Temple is small and very nice looking. Within the temple we'll see small wells which are very deep. This place is Shiva-shakti-peeth. The Shaktipeeth present here is called as as Tara peeth. Shiva is Golakeshwar. Another Shiva linga of Mangaleshwar is also present here. We can't see the Shiva lingas. They are present within the wells. Brahmarshi Vasistha is believed to be present here in the hidden form.
Sandhya Lalitha and Kantha are three parts of a rivulet (described as three different rivulets in Kalika Purana) present behind Vasistha temple. The junction of these three rivulets is called as Amrutha kunda, bathing in which increases the longivity of life.
There is an important temple of Arundhati mata (The wife of Vasistha maharshi) on this hill.
Once upon a time, Vasistha went to Kama rupa to worship Goddess Kamakhya. But, the king Naraka didn’t allow him. He became angry, and cursed Naraka that his dynasty will fell down in near future. He built a hermitage at Sandhyachal and lead his life meditating on Shiva.
The name Sandhyachal came from the Goddess Sandhya who did Tapasya there. Sandhya is the daughter of Lord Brahma(Manasa putri) . She was so much beautiful and born in young age. Lord Brahma and his sons(Saptharshis) combinely fell in love with her. She too loved Vasishtha, one of the Saptharshis. Lord Shiva observed it and stopped them. Sandhya felt shy. She wanted to purify herself. She did a big Tapasya for Lord Shiva. She asked Shiva a boon, that nobody should born in young age and shouldn’t get the feelings of love by birth. From then onwards, the humans got childhood in their life.