The urban heart of the city is often choked with smog that blocks the morning sun and drains the sky of its pastels. The pollution from the countless factories and laboratories is constantly spewed into the environment. It is a place both supported and ruined by unchecked industry, mercantilism, and magic run amok. Stifled inventors often find their unorthodox research welcomed in Zaun, but reckless industry has rendered whole swathes of the city highly toxic. Zaun is a polluted undercity located beneath Piltover - once united, they are now separate, symbiotic cultures.

Streams of toxic runoff stagnate in the city's lower reaches, but even here people find a way to exist and prosper. Unfettered development of volatile technologies and reckless industry has rendered whole swathes of Zaun polluted and dangerous. Many of the goods coming to Piltover find their way into Zaun's black markets, and hextech inventors who find the restrictions placed upon them in the city above too restrictive often find their dangerous researches welcomed in Zaun. Piltover's wealth has allowed Zaun to develop in tandem a dark mirror of the city above. Though it exists in perpetual smogged twilight, Zaun thrives, its people vibrant and its culture rich. Zaun and Piltover were once united, but are now separate, yet symbiotic societies. What light reaches below is filtered through fumes leaking from the tangles of corroded pipework and reflected from the stained glass of its industrial architecture. Zaun, also known as the City of Iron and Glass, is a large undercity district lying in the deep canyons and valleys threading Piltover.

Living earth league city