Twenty-five (25)

Tango outside the big cities is often sparse.  The dedicated few travel between them, like oases in the desert.  But our desert consists of motorways and highways and freeways and country roads and coastal roads.

The oases are so refreshing, though, that we make the journeys willingly.  Then we worry about our carbon footprints.

The M25 links much of the tango in the South-East of England.  And if it doesn't, it links to a motorway that does.