 The "Kularnava Tantra" mentions 18 Pithas and mentions Varanasi as the sixth one.The "Ashadashapitha" (18 Peethas) ascribed to Shankaracharya (interpreted as Adi Shankara, however probably Shankara Agamacharya, Bengali author of the "Tara-rahasya-vrittika") enumerates 18 names along with their presiding deities or "Pitha-devi"s including Vishalakshi of Varanasi as the fifth Pitha.In the "Kubjika Tantra", Varanasi is third in 42 names.