Two lines of electricity pylons cross the Olympic Park site.
They will have to go during the transformation of the area from industrial wasteland to urban park. 'The pylons are very visually intrusive and the aspiration has always been to get rid of them, ' says Buro Happold senior associate Ken Carmichael.
The lines are owned by National Grid and EDF.
Although a vital part of London's energy network, they are visually intrusive and restrict scope for development beneath their path.
The pylons take up land space, and their presence is a major deterrent to housing developers as there are concerns about the health effects on people living close to electricity cables.
If London gets the Games, or failing that, when regeneration eventually takes off, the cables will be buried.
Buro Happold has explored the options for cable burial, ranging from putting them in a shallow trench, to hiding them in a bored or cut and cover tunnel likely to be around 6km long.
The tunnel option looks to be the favourite. Although more expensive, it allows easier access for maintenance and re-laying and also reduces the need for excavation.
Cut and cover would be the cheapest yet most disruptive option for construction of the tunnel.
But it must cross the busy A11 trunk road, which cuts through the site. Avoiding this would be difficult for the cut and cover option and would make it more expensive.