The Tunnels Under Our Feet: Colorado's Forgotten Hollow Sidewalks

Have you ever seen a manhole cover with little glass circles in it and wondered why it was different from the others? Did you know that there were actually tunnels under the sidewalks and those manhole covers imbedded with glass circles allowed light into the tunnels below?



Underground hollow sidewalks and vaults had many uses when they were first installed in the late 1800s. Vaults allowed businesses to expand and utilize the unused spaces beneath sidewalks and alleys for storage and coal delivery. Hollow sidewalks allowed for delivery of merchandise, to allow people to travel from one place to another without being seen (think prostitutes and speakeasy's during Prohibition), and to allow construction of below ground shops. Hollow sidewalks were shared by all the buildings on a block.



The author spent 5 years researching these tunnels and she covers fourteen cities in Colorado that has them. The book includes a listing of tours of the historic underground across the U.S.