Originally posted at Blogging.la

One of the oldest spans across the Los Angeles River, the 7th Street Bridge dates back to 1910 when the at-grade version included two-sets of trolley tracks. It quickly became one of the most congested ways across the river and by the late 1920s it was decided that rather than demolish the entire structure, a second level would be built on top giving it a double-decker appearance and allowing traffic to move freely without being impeded by any freight trains traveling  through.

Ever since I first noticed that open but inaccessible lower level of the 7th Street Bridge about eight years ago, I’ve wondered what it’s like inside, and my curiosity only increased a couple years ago when LA River advocate Joe Linton found a way in and wrote about it on his blog LA Creek Freak. It again was piqued a few months ago when the news hit that there are plans in the very early stages to convert the space to an open-air market.

During a visit paid to the bridge last summer while on one of my riverbed rides, I couldn’t figure out how Linton got up there, and I had pretty much reconciled that the space was to remain off limits to me — until a couple weeks ago, when an acquaintance of Linton’s contacted me out of the blue and said she knew how he got in and would I be game to try. Of course I would, I said.

And so it is that I strapped my GoPro cam to my chest and this timelapse came to be. But it almost didn’t. When “Squeaky” and I first showed up, we found railroad ties leaned up below a grate-covered opening from which dangled a rope, but the grating looked locked. Back at our bikes and preparing to leave, a gentleman approached the opening and in a matter of a few seconds had clambered up the tie, pushed open the grate and made his way in. Squeaky quickly hustled over and struck up a conversation with him and asked if it was OK if we came up and looked around. He was hesitant, but said he wouldn’t mind. Squeaky went up first, but the bike shoes I was wearing wouldn’t allow me to get up the steeply angled tie so I had to improvise and add another “step” with another large tie that reduced the angle.

And in I went to enjoy one of the most unique urban explorations Los Angeles has yet to offer me.

Probably the coolest find inside: A construction worker stylistically carved his mark (DM No. 1 – 1927 – Chicago) into the concrete during construction of the second level.

If you want to skip ahead to the point where Squeaky climbs up, it’s at about 4:40. I reconfigure the ramp and make my ascent just after the 5:00 mark. But from wherever you check it out, this timelapse of us wandering around gives a pretty unique picture of what the space is like in there.

The flat version below of a 360-degree panorama I made from inside can be interactively rotated through here: