Today, the highest detail level is giving a patchwork of map tiles, half
from the most recent map and half from the previous one... the colouring is
different, so it is easy to tell which tiles are newer and which are older,
particularly if the boundary between new and old runs through Euston
Station. Every time you hit Refresh (F5) you get a different selection, and
the two coloured halves of Euston swap around.