Thanks for these responses, everyone!

Here are links to TinyPic where I've posted three photos, one is a zoom
on the leaves, the next is the trunk of the tree, last is a long shot of
the tree -- it's taller than the two-story terrace houses around it
(it's in someone's back garden).

'Image - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting'
(http://tinypic.com/r/255kpcj/9)

'Image - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting'
(http://tinypic.com/r/wvs4t4/9)


'Image - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting'
(http://tinypic.com/r/i2txc0/9)

Eucalyptus certainly, but which one? From memory it could be Viminalis? I
had one many years ago but it blew down in a gale at about half that height!