Secrets of China's Forbidden City

Beijings Forbidden City is a huge, walled palatial city within the new (more northern and eastern) capital chosen over Nanking by the great Ming emperor Chengzu Yongle, who seized the throne in 1402 from his elder brothers son by military coup. It symbolizes the vast empires then unequaled wealth and power, being the largest palace ever in the world, with halls worthy of the mandate of heaven, impressing any foreign delegation, accommodating thousands of courtiers, public/domestic servants and guards. This required crushing taxes and over a million laborers for most of his reign (until his death in 1424), using the best craftsmen and the finest materials, sparing no expense nor imports (like pigments from Europe), and innovative ways to produce and transport (partially on ice). It would require near-constant maintenance -modern restoration contributes to and benefits from studying its secrets- and frequent rebuilding, mainly after fires, but astonishingly survived well hundreds of seismic shocks, thanks to a brilliant, complex system of leading pressure from shaken pillars (with lose bases) and heavy roof structures to elaborate shock-breaking woodwork with intricately interlocking parts.