Canto 3 -
Araṇya-kāṇḍa
Chapter 60: Rāma Searches for Sītā
Text 3.60.37

स वनानि नदीः शैलान्गिरिप्रस्रवणानि च।
काननानि च वेगेन भ्रमत्यपरिसंस्थितः॥

sa vanāni nadīḥ śailān giri-prasravaṇāni ca
kānanāni ca vegena bhramaty aparisaṁsthitaḥ

saḥ = He; vanāni = the forests; nadīḥ = rivers; śailān = mountains; giri-prasravaṇāni ca = waterfalls 2; kānanāni = woodland; ca = and; vegena = speedily; bhramati = ran through; aparisaṁsthitaḥ = in restlessness.

In restlessness, He speedily ran through the forests, rivers, mountains, waterfalls and woodland.

The forests were easy to pass through while the woodlands were difficult to pass through.