Valmiki Ramayana Yuddha Kanda Sarga 42 Shloka 15

ते they (Vanaras ), द्रुमैः trees, पर्वताग्रैश्च peaks of mountains, मुष्टिभिश्च even with fists, प्लवङ्गमाः monkeys, प्राकाराग्रा top of boundary, अरण्यानि forests, ममन्थुस्तोरणानिच gateways of the city

With the means of mountain peaks, as well as their fists, the Vanaras scaled the boundary walls and gateways of the city.