Shiva Purana
पश्चिमाम्बुधितीरस्थं गोकर्णं तीर्थमुत्तमम् ॥ तत्रास्ति शिवलिंगं तन्महापातकनाशकम् ॥ ४४॥
The excellent holy centre of Gokarṇa is on the shore of western ocean. There is a phallic image of Śiva, destructive of great sins.
english translation
pazcimAmbudhitIrasthaM gokarNaM tIrthamuttamam ॥ tatrAsti zivaliMgaM tanmahApAtakanAzakam ॥ 44॥
hk transliteration by Sanscript