I recently toured the New York City Second Avenue Subway construction site with Monica Bradley, Scientific American's photo editor, and photographers Jeremy Floto and Cassandra Warner. Wearing hard hats and boots, we climbed five stories down a rickety set of stairs and emerged inside the cavernous construction site that will eventually form the East 96th Street station. The ground is wet and muddy, and if you stand in the middle of this vast hole in the ground and look up to its entrance, you can glimpse the tops of the tenements that line Second Avenue. Here are some outtakes from the July photo feature that ran in Scientific American magazine.

» View the Second Avenue Subway Photo Tour