Each evening a giant Advent calendar is projected onto the face of General Register House with pictures of Edinburgh winters dating back to the 1700s taken from archives in the Historic Environment Scotland, Scotland National Records of Scotland and National Library of Scotland. Two people seem to pull down screens or open sliding doors to reveal pictures of a particular year throughout the 24 days accompanied with music from that period.
Clicking on a day in this link is well worth a look showing the clever projections with a variety of images.  Amazingly the pictures appear to be projected from just in front of the building but this is a site of a very busy road so they are cleverly manipulated from the top of the old Post Office building which is actually opposite the end of the building.