Toronto Is Hiding an Ancient Shoreline Nobody Talks About

A 15-metre cliff runs right across Toronto, from the Humber River all the way to Scarborough, and most of the people living on top of it think it's just a hill. It's actually the shoreline of Glacial Lake Iroquois, cut by waves roughly 12,000 to 13,000 years ago while a wall of ice still blocked the St. Lawrence. Casa Loma sits on its edge, the Baldwin Steps climb 23 metres of it, and Davenport Road bends because people walked its old beach for thousands of years. We trace the line street by street, from a LiDAR terrain scan to one man's pandemic survey, and see how the city graded it, mined it into bricks, and in places erased it. Then we go back to the ice to answer the strangest question of all: why is this shoreline higher in the east than in the west, and what does that reveal about the ground under Toronto that is still moving? 👉 Spotted a piece of this old shore in your own neighbourhood? Tell us where in the comments. 🔔 Subscribe to Lost Canadian Towns for more of Canada's hidden places: the towns, the roads, and the coastlines time left behind. Chapters 00:00 Intro – The Hill That Isn't a Hill 00:49 Welcome – A Lost Coastline in Canada's Biggest City 01:37 The LiDAR Scan – One Long Step Across Toronto 03:28 Known for a Century – So Why Has No One Heard of It? 04:03 Paul Smith – Walking the Old Shore in a Pandemic 05:42 Where the Line Vanishes – Leaside to the Rouge 06:15 Baldwin Steps & Casa Loma – Living on the Cliff 07:27 The Spadina Expressway – The Bluff That Almost Wasn't 07:57 Mined Into Bricks – Gravel Bars & the Leaside Lagoon 09:31 Davenport Road – An Ancient Portage Trail 10:58 The Ice Age – How Glacial Lake Iroquois Formed 12:17 How Long Ago? – Untangling the Dates 12:56 Storm After Storm – How Waves Cut the Cliff 14:34 The Dam Breaks – The Plunge to Lake Admiralty 15:24 The Mystery – Why Isn't the Shore Level? 16:37 Postglacial Rebound – The Ground Springs Back 17:27 Still Rising – Centimetres per Century 19:28 Back to the Scan – Final Thoughts 21:55 Outro Lake Iroquois, Glacial Lake Iroquois, Toronto shoreline, Iroquois shoreline, Baldwin Steps, Casa Loma, Davenport Road, Toronto history, Toronto geology, ancient shoreline, postglacial rebound, Lake Admiralty, Toronto LiDAR, Lake Ontario history, Ice Age Ontario, Lost Rivers Toronto, hidden Toronto, Toronto hidden history, Spadina Expressway, Canadian geology, Lost Canadian Towns, Canadian history, ice age #Toronto #TorontoHistory #LakeIroquois #Geology #IceAge #HiddenHistory