Pittsburgh Skyline

PPG Place, finished in 1984, is Philip Johnson's neo-Gothic experiment: a cathedral silhouette executed entirely in mirrored glass, carrying 231 spires across its six buildings, the tallest reaching 82 feet above the roof. Nothing else in any American skyline looks like it.

It is also the element that decides whether a Pittsburgh model works. Those spires are thin, numerous and clustered, which is the hardest combination to print cleanly — too fine and they snap, too thick and the whole tower reads as a lump rather than a crown.

The U.S. Steel Tower, the tallest in the city, is clad in Cor-Ten weathering steel — an alloy that corrodes on purpose, forming a stable rust layer that protects the metal beneath and never needs painting. The building was effectively a product demonstration by a steel company, and its deep brown is nothing like the grey and glass around it.

Set that against PPG's mirrored spires and the triangular point of land where the Allegheny and Monongahela meet to form the Ohio, and Pittsburgh has the most geographically constrained downtown of any city here. The rivers are not scenery; they are the reason the Golden Triangle is shaped the way it is.

The Golden Triangle fills the frame because there is nowhere else for the city to go. The U.S. Steel Tower leads at 841 feet, a blunt triangular mass in rust-brown weathering steel. BNY Mellon Center stands beside it in granite, and the Gulf Tower's stepped pyramid crown — modelled on the Mausoleum at Halicarnassus and lit by colour to forecast the weather — closes the eastern side.

PPG Place is the one that does the work: six buildings in mirrored glass carrying 231 spires between them. The two rivers meet at the point, and Point State Park's fountain marks the tip where the Allegheny and Monongahela become the Ohio.