Oh interesting! I glad it sparked a bit of a treasure hunt. Being able to incorporate all these different disciplines is a pleasure, especially when you travel through a land and know it has a history but you are grasping at straws sometimes to put your finger on it. Some of those elements are the flora and fauna, perhaps the ruined buildings and their substantial hints to history, maybe even the nature of the paths and trails in the area. Often when you go back more than a few hundred years those ruined buildings begin to fade (or more likely - the stone has been repurposed for other projects) and the archaeological findings are well picked over, so what are we left with?..
.. The humble topo map of course and a host of placenames which are themselves rich in history even if they're often a little obtuse upon first reading. I'm fortunate enough to have some of the early 1890-1915 topo maps of the North West (the ones on canvas) and being able to look at not just the character and aspect of the ground but also the history of what that area was known for is a fantastic way to keep surprising yourself - even with an area you thought you already knew everything about.