London really does it up with lights in the darkest months of the year. They begin wonderful Christmas light displays in November (in 2010 we were there and got to see them...fabulous!) and they now have this festival in January.
I've posted a few photos but really worth taking a look at all of them.
http://www.telegraph.co.uk/news/picturegalleries/12101804/Lumiere-London-2016-The-UKs-largest-light-festival-in-pictures.html?frame=3550330
Westminster Abby