In a moment of typical year-end reflection I’ve been wondering what creates the most lasting travel memories. Two categories dominate my travels:  (1) trips for pure personal joy and (2) treks to places of historical and cultural significance. I tend to come down with the latter as most memorable. I’m interested in your thinking.

Perhaps my two most profound American travel experiences were years and miles apart, yet they’re forever prominent in my mental scrapbook for their blots on modern history. And let’s face it: Things that happen in your adult lifetime etch the deepest memories.

A cold rain drizzled from a sad, grey sky when I stood at a decorated fence protecting Ground Zero in Lower Manhattan a few months after those two commercial jets, piloted by foreign religious zealots, brought down the World Trade Center twin towers. There was nothing but a gaping hole in the ground back then. Ribbons and photos and flowers bedecked the chain link. Rehabilitation of the site will apparently include a victims’ memorial when completed years from now. Progress disappoints me.

Then, much more recently, a brilliant sun blazed and a swirling wind created a convection oven as I made my solitary way around the memorial to 168 victims of a 27-year-old mass murderer previously decorated in war by the U.S. Army. The Oklahoma City National Memorial to the 1995 federal building bombing is one of the most beautiful and moving places I’ve stood upon as a traveler. I hope they can achieve as provocative an effect in Manhattan. If you can stand in the museum room dedicated to the children who died that day and not weep you just aren’t human.

So I wiped away tears on both those trips. I’ve laughed and ached with joy and laughter on plenty of others. You know which I remember best. What about you?