It's a belladonna lily (Amaryllis belladonna if you want to be formal) and it gets the name of 'naked lady' from the way the flower spike seems to appear out of bare ground. Actually it grows from a bulb which doesn't put out leaves until it has flowered.
When I said it was dancing I wasn't joking. Getting the photo was quite a challenge because we've been having strong wind gusts that meant the first umpteen photos were blurred. Finally, though, I got this one which is just about clear. I love the way the centre of the blossom positively glows in the sunlight.
These lilies are often called Easter lilies here because they used to appear at about then. Now that our weather has changed so much - we've just had the second wettest day on record (over a hundred mms in twenty four hours) and the coldest February day on record (a maximum of 17.4 C) at a time of the year when we'd usually be expecting dry and hot (mid thirties) - the poor lilies are totally confused and so we have them flowering early in February.
Lovely as they are, they do have a dark secret. The sap and bulb are both toxic so if you have young children visiting your garden you need to be watchful to make sure they don't chew on it or come in contact with the sap.