In Spain, So Here's London

We are in Almeria, Spain after having visited Granada, Spain.  We are here for the 3W Seminar.  More on that later.  Both the cities of Almeria and Granada were at one point conquered by the Muslims.  These cities were filled with mosques for centuries, until "the Catholic Kings" reversed the tide and Spain became "Christian" again.  The walls and fortresses are still present in Almeria and Granada.  It is so European in that there are layers and layers of ancient, complicated, fascinating history everywhere you look.
My favorite place on Earth---London---is the same exact way.  Here's a video that shows how this ancient layered history still has effects in the present day.  So much of Europe is exactly like this video.