Ramayana 2.28.10

लताकण्टकसङ्कीर्णाः कृकवाकूपनादिताः।निरपाश्च सुदुर्गाश्च मार्गा दुःखमतो वनम्।।2.28.10।।

latākaṇṭakasaṅkīrṇāḥ kṛkavākūpanāditāḥ | nirapāś ca sudurgāś ca mārgā duḥkham ato vanam ||

The paths are choked with thorny creepers, resounding with the cries of wild birds, waterless and extremely hard to traverse; therefore the forest is a place of suffering.