Happy 150th birthday to London Underground. From Google:
I love the London Tube map with its continuous evolution based on the original by Harry Beck and many Londoners do feel strongly about it. Not that long ago, when they tried removing the river image there was outrage. What a relief therefore, that Google has done a pretty good job of it!
The doodle only appeared on the UK search page but there is now an archived version on the doodles site!