Being up at Twin Peaks, there were plenty of interesting things to look at.  San Francisco is a city with such great terrain which is obvious when you are moving around the city but which gets lost as you view things from a distance.  The view from the top of the hills includes the various rocky outcrops but you do lose a little perspective on the steepness of things.  However, as I looked around, I could see various locations where the houses were climbing the available ground and finding their spot, however precarious.  I used a longer focal length to try and show just how they were stacked up on each other and the terrain.  The odd rock face right behind them or the house immediately below looked fascinating to me.  I suspect this is something I will be seeing a lot more in time.