Valmiki Ramayana Yuddha Kanda Sarga 71 Shloka 74

अथ now, लक्ष्मणेषुप्रपीडितः tormented by Lakshmana's arrow, राक्षसः Rakshasa, रुद्रबाणहतम् as though struck by arrow of Rudra, घोरम् dreadful, त्रिपुरगोपुरंयथा like the gate of Tripura, प्रचकम्पे shaken.

Now tormented by Lakshmana's arrow the Rakshasa was shaken dreadfully like the gate of Tripura (the city built of gold, silver, and iron in heaven, in space and earth by Maya and burnt by Rudra).