Potterheads will already know that nine lamppost-sized wands have appeared on St Peter's Hill — between St Paul's Cathedral and Millennium Bridge.
They light up at 6.45pm each night (to a short musical introduction) and are there till 13 November, promoting J.K. Rowling's charity, Lumos, and the new Fantastic Beasts film, The Crimes of Grindelwald.
Every Wednesday is a 'Wizarding Wednesday', where fans gather round for special treats around the wands.
It's totally free, and your kid (or partner) will totally love you for taking them along.
These pictures are from the Wizarding Wednesday on 31 October, which features tales of the wands and the dark arts.
You can catch the final one on 7 November, when a marching band will play Potter-themed music, from 7.20pm. To get a good spot, we recommend you get there early.