(n) a location where a rail or tube line coincides with at least one other mode of public transport, and provides the necessary planning context for the development of a tall, or very tall building, usually in isolation from its wider urban context. The existence of towers in the most unlikely places (eg Whetstone; Cockfosters) suggest this may be a rare example of an regeneration law, and ongoing research is beginning to reveal a positive mathematical relationship between numbers of rail and bus routes, and the height of the building – but also an inverse mathematical relationship with its long term sustainable management,and the value it brings to its surrounding area