Two years (and 11 days) to go
How does one of the biggest building sites in the world show that it'll be soon be ready to stage the biggest global sport event?
That challenge is facing the organisers of the London Olympics as we head for yet another major milestone: the "Two Years To Go" mark on 27 July.
Now that South Africa's World Cup is just a memory, it's London that will be moving to centre stage - and we're about to have a test of that readiness, and our most detailed look so far at the construction work.
The London Olympic Park promises a legacy of regeneration for East London
On the 27th, the Olympic organisers are going to show that some of the venues are close to usable - within the rather obvious limitations of much of the Park infrastructure not being ready and a few thousand site workers still being hard at it with many months of labour still to come. But the aim is that we'll see some top athletes in action in the 2012 arenas with highlights including a bike whizzing round the track at the Velodrome - and the first sprint on a track within the main stadium. Indeed, we can confirm that the man performing there will be Michael Johnson - the gold medal hero of the Atlanta Games and BBC Sport's top athletics pundit.
The range of what's being planned means the BBC will be offering extensive coverage through the day of the 27th.
Many of our TV and radio shows will be live from the Olympic Park, and there'll be a special programme on BBC One at 2.15 in the afternoon with Sophie Raworth and Jake Humphrey reporting live on the inaugural event in the stadium and reflecting all the activity going on.
As a further sign that our own preparations are bowling along, we have two major launches ourselves that day. We'll be revealing the new BBC London 2012 website - which will bring together all the information about 2012 in one place, so covering not just sport but also news and culture and events. And World Olympic Dreams will go live as part of that site, along with the start of its appearances on BBC News programmes in the UK and across the globe. I've seen some of the films and I think you'll like them: there are some extraordinary tales about to be told.
So "Two Years To Go" should have a lot to offer. Our first live outside broadcast of sport from the Olympic Park, and - if all goes well - the chance for the organisers to show that the seven-year journey from Singapore to London is close to entering its most critical stage.
Amid the adrenalin and excitement, there are still plenty of sceptics to be won over; and the battle for the hearts and minds of the British public is part of what will be played out in Stratford on the 27th.