Beneath Boston’s City Hall Plaza lies a forgotten 1898 streetcar tunnel — a sealed remnant of America’s first subway. What began as a desperate solution to 19th-century gridlock eventually evolved into a hidden web of corridors, platforms, and portals stretching beneath the city. From the Pleasant Street Portal to the long-lost tracks of Scollay Square and Adams Square, these underground passages once powered one of the largest streetcar systems in the United States. In this episode, we trace Boston’s evolution from a crooked colonial peninsula to a booming streetcar metropolis, uncovering how the rise of electrified rail led to the nation’s earliest subway infrastructure. We explore how modernization, automobiles, and shifting political priorities ultimately sealed off entire sections of the network — leaving behind abandoned chambers, hidden platforms, and tunnels that still sit below modern streets. Learn more about your ad choices. Visit megaphone.fm/adchoices