This is a photo of the the Buerger Center at Children's Hospital of Philadelphia. I used a Lee Big Stopper 10-stop ND filter which created the sky movement and I edited the photo in LR and Photoshop.

Canon 5d Mark iii - Canon 16-35 2.8 @ 29 mm, 30sec, F22 and ISO 800 - Lee 10-stop ND filter