NYC's East Side Access Project continues apace, and these recent images, taken last month by MTA photographer Rehema Trimiew, show a whole new view of the mind-boggling underground caverns now being constructed beneath Manhattan. From raw walls of exposed geology to this, the space is finally taking on the look and feel of architecture.

Like some unacknowledged installation by artist Olafur Eliasson—known for, among other things, his all-yellow Room for one colour—the results are a colossal, other-worldly chamber populated by tiny human forms and diminutive digging machines. The fact that, in real life, this mechanical equipment would itself be the scale of a small building only indicates the massive and dream-like scale of this place.

The titanic yellow facility—its walls secured behind waterproofing geotextiles that will, of course, eventually be covered over altogether, meaning that this surreal yellow scene is just a temporary state—is on the Grand Central side of the project, and will be part of a huge new underground terminal increasing access for the Long Island Railroad. It is also just one of the many other, ongoing works tunneling away beneath the surface of the city.

Look upon New York's wondrous subterranean works, my friends, and swoon. [MTA]

All photos: MTA Capital Construction / Rehema Trimiew