Valmiki Ramayana Yuddha Kanda Sarga 22 Shloka 61
Original Shlokaनलश्चक्रेमहासेतुंमध्येनदनदीपतेः । सतदाक्रियतेसेतुर्वानरैर्घोरकर्मभिः ।।6.22.61।।
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नलः Nala, नदनदीपतेः Lord of rivers, मध्ये centre, महासेतुम् huge bridge, चक्रे started, तदा then, घोरकर्मभिः terrific task, वानरैः with Vanaras, सेतुः bridge, क्रियते built.
Nala started the task of building the huge bridge in the centre of the ocean with Vanaras.