Director Fernando Coimbra shared the photo above and stated briefly: "Day 1."
Screenwriter of the movie, Christopher Roessner also confirmed the filming has begun:
production day 1 in the can. sleep now.— Christopher Roessner (@CitizenRoessner) November 1, 2015
Last Thursday, Henry shared a video that shows the process of his transformation into US army captain. For his role in this film Henry shaved his head, while preserving his beard. Two days ago, the director posted on Facebook: "News from the front. Sand Castle taking shape. Incredible week of tests with the actors." with a link to this news.
Sand Castle, starring Nicholas Hoult, Beau Knapp, Glen Powell, Logan Marshall-Green, Neil Brown Jr., and Henry Cavill, tells the story of American soldiers in Iraq who attempt to save a village at the risk of their own lives. The movie is slated to release in 2016.