When Apple first unveiled plans for its new spaceship-shaped mega-campus it looked more like sci-fi concept art than an actual blueprint. But three years later construction is almost complete on Cupertino company’s exciting new headquarters.

A recent drone video, shot in 4K by Matthew Roberts, shows the latest progress at the construction site. The main circular office building is almost complete. You can see some of the massive curved windows already in place, along with solar panels on the roof.

We get a look at Apple’s planned R&D facility, which is coming along nicely. The company’s new subterranean auditorium is visible, with a modern entrance above ground. There’s also a 100,000 square foot fitness center, and several parking garages that can hold 11,000 cars total.

Once the buildings are complete, Apple will still need to cover the 2.8-million square foot campus in greenery. The official plans call for more than 7,000 trees and a forested garden at the center of the main building where employees can relax in a secluded natural environment.

Apple’s multi-billion dollar campus should be complete by the end of 2016, and the company plans to move in early next year.