Thanks for the book list! I'll get reading. It certainly does give a very different perspective, the geometry is so much easier to work out. Walking through the earthworks, there's clearly been a lot of activity there at some point, but it's only from the air that I got the true perspective!

There are several flying locations near or at ancient sites, I'll be taking much more notice this year.

Hopefully I'll be able to post some shots over the summer, although if it's as rough as it was last time I'll need both hands just to hang on to the glider!

Thanks again,

Richard