From the MTA: “1 of 2 caverns that will house LIRR platforms and tracks underneath the lower level of Grand Central Terminal.” More photos
Work on the 7 Subway Extension [MTA photo; via Benjamin Kabak]
Building at 1830 Second Avenue, outfitted with several retroflector tags (in the blue circles) which are repeatedly and automatically surveyed to check for building movement due to work on the Second Avenue Subway. Photo from The Launch Box: Retroreflectors Everywhere, where much more information can be found.
Visualization of the north end of Union Square Park after the current construction project is finished, seen in the image gallery at the project web site. The project site also features regular construction updates. [via]