Valmiki Ramayana 5.2.22

मन्सेव कृतां लङ्कां निर्मितां विश्वकर्मणा ।द्वारमुत्तरमासाद्य चिन्तयामास वानरः॥

manseva kṛtāṃ laṅkāṃ nirmitāṃ viśvakarmaṇā |dvāramuttaramāsādya cintayāmāsa vānaraḥ ||

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