The massive megastructure built for eternity and still standing 1,700 years later | CNN

Jetavanaramaya, a colossal fourth-century Sri Lankan stupa, was once among the world’s largest structures, a vast and ancient brick-built engineering marvel that has endured earthquakes, neglect, and civil war. Completed in 301 CE, it was the third-largest man-made building on Earth, surpassed only by the Great Pyramids of Giza. Despite centuries of collapse, abandonment, and restoration, it remains the largest brick structure by volume ever constructed.