Well, we say mystery, but we're about to tell you everything so it's a short kind of secret.

The heritage centres around a classic thing of beauty - The glass bottle designed by Coco Chanel, based on the Place Vendome in Paris where she often stayed at The Ritz. See?

Until now the fresher Chanel No. 5 Eau Premiere was not available in the classic bottle shape, but to mark the 5th of the 5th it's upgrading. To celebrate Chanel have installed a Mystery Bottle all over the UK, a sensory experience where you can literally waft through a mist of perfume. Like Lily Allen did last night in Covent Garden:

So, the secret is out. Find a giant bottle to waft through, then go to a Chanel counter for a fragrant keepsake. We won't tell you what - got to keep the mystery alive you see...