Valmiki Ramayana Sundara Kanda Sarga 61 Shloka 8
Original Shlokaयत्तन्मधुवनं नाम सुग्रीवस्याभिरक्षितम्। अधृष्यं सर्वभूतानां सर्वभूतमनोहरम्।।5.61.8।।
1 source checked for this shloka
अभिरक्षितम् wellprotected, सर्वभूतानाम् all creatures, अधृष्यम् difficult to access, सर्वभूतमनोहरम् enchanting to all beings, यत् that, सुग्रीवस्य Sugriva's, मधुवनं नाम Madhuvanam, तत् that.
The Madhuvanam of Sugriva was wellprotected and was difficult to access for the vanaras. It was enchating to all beings.