Valmiki Ramayana 6.68.16

ध्रुवमद्यैव संहृष्टा लब्धलक्षाः प्लवङ्गमाः।आरोक्ष्यन्ति हि दुर्गाणि लङ्काद्वाराणि सर्वशः॥

dhruvamadyaiva saṃhṛṣṭā labdhalakṣāḥ plavaṅgamāḥ |ārokṣyanti hi durgāṇi laṅkādvārāṇi sarvaśaḥ ||

Our plain-language meaning of this verse is waiting for scholar review.