Valmiki Ramayana Aranya Kanda Sarga 39 Shloka 4

रावण Ravana, अत्यन्तघोरः very dreadful , अग्निहोत्रेषु at the sacrificial sites, तीर्थेषु at sacred rivers, चैत्यवृक्षेषु alter at the root of fig trees in sacred places, तापसान् ascetics, सम्प्रधर्षयन् torturing, व्यचरम् I wandered.

O Ravana, assuming a very dreadful form, I wandered about sacrificial spots, sacred places, river banks, under huge trees planted at quadranglestorturing the ascetics.