I would like to share my Theory of how the cauldron is lit and where it will sit.
I have just returned from the dress rehersal for the opening ceremony and I have to say it is amazing!!
Point 1 - However, there was one part of the stage that has been left out, on recent pictures of the stadium the centre stage has the river thames on it, during the rehersals this has never been used or seen.
Point 2 - There is a platform installed above the main stage at the North End of the Stadium, it sits empty and looks wide enough and big enough for an object (maybe a cauldron) it wasn't there a few weeks ago, but it is there now.
So, my theory (and this is only a theory, so please don't shoot me down) whoever the final torch bearer is will point the torch to river thames marked out on the stage and the river will burn, a river of fire, snaking its way was the thames does to a cauldron which currently is hidden under the stage at the end. The cauldron will then be lit and raised to the roof, to the platform, at the north end...
As I say it is only my theory, and of course I could be so so so so so so so wrong, but thought I would share with you lovely people on here!!