The Large Synoptic Survey Telescope has been a long time in the making when work on its mirrors started in 2007. It's finally coming together, though. The LSST team has released a brief clip showing progress on the Chilean facility as of the end of 2017. Not surprisingly, it's huge -- that giant 3.2-gigapixel camera (potentially the largest in the world) and ultra-wide optics (3.5 degrees in diameter) take up a lot of space by themselves, let alone the rest of the complex.
As far as the LSST has come, it has a long way to go. It won't see engineering first light (that is, first actual use) until 2019, and its 10-year survey won't start until January 2022. This is more a preview of what astronomy will be like in the next decade. Between this and the Giant Magellan Telescope, scientists will capture an unprecedented level of detail that promises to reveal elements of the universe that just weren't detectable before.