Matsya Purana — The Burning of Tripura and Rudra’s Victory
सगोपुरो मन्दरपादकल्पः प्राकारवर्यस्त्रिपुरे च सो ऽथ तैरेव सार्धं भवनैः पपात शब्दं महान्तं जनयन्समुद्रे //
sagopuro mandarapādakalpaḥ prākāravaryastripure ca so 'tha taireva sārdhaṃ bhavanaiḥ papāta śabdaṃ mahāntaṃ janayansamudre //
That fortified city, complete with its gates, founded like the foot of Mount Mandara and encircled by most excellent ramparts, then in Tripura fell into the ocean together with those very palaces, raising a tremendous roar.
It depicts a destruction motif: an entire fortified city (Tripura), with gates, walls, and palaces, collapses into the ocean, emphasizing catastrophic dissolution through submergence.
Indirectly, it underscores the impermanence of even the strongest royal constructions—an ethical reminder in Purāṇic literature that power and wealth must be governed by dharma, not pride in fortifications and possessions.
It names key Vāstu/urban elements—gopura (gateways) and prākāra (ramparts)—and uses Mandara-like foundation imagery, highlighting ideals of massive bases and strong enclosure walls in Puranic city-planning descriptions.