Matsya Purana — The Slaying of Jambha and the Rise of Tāraka: Divine Battle Formations
एकप्रहारकरणैर् अप्रधृष्यैः समन्ततः गन्धर्वनगरं तेषु गन्धर्वास्त्रविनिर्मितम् //
ekaprahārakaraṇair apradhṛṣyaiḥ samantataḥ gandharvanagaraṃ teṣu gandharvāstravinirmitam //
All around, it was made unassailable by defensive contrivances that could repel with a single stroke; and within those defences stood a “Gandharva-city”, fashioned by Gandharva-weapons—superhuman, magically engineered armaments.
This verse is not about Pralaya; it describes protective construction—how a city can be rendered “unassailable” through powerful defensive devices and astric (weapon-based) safeguards.
It supports the king’s rajadharma of protection: establishing secure settlements and fortifications so the populace remains safe from invasion and disorder.
Architecturally, it points to a fortified-city concept (nagara-vinyasa) with perimeter defenses; ritually/technically, it alludes to astric protections (gandharvāstra) as a Puranic idiom for advanced, quasi-magical security measures.