Shiva Purana
सिद्धक्षेत्रे महापुण्ये शिखण्डी नाम पर्वतः ॥ शिखण्डिनो वनं वापि यत्र सिद्धनिषेवितम् ॥ २१ ॥
In the very sacred holy centre of achievements there is the mountain Śikhaṇḍin, where the forest is resorted to by the Siddhas.
english translation
siddhakSetre mahApuNye zikhaNDI nAma parvataH ॥ zikhaNDino vanaM vApi yatra siddhaniSevitam ॥ 21 ॥
hk transliteration by Sanscript