The Colosseum at midnight.
In 2003, I lived in Rome
and loved to take late-night walks to this nearby amphitheater. The grandness of the structure is only increased at night and a large, flat rock outside its walls was a perfect place for me to pause and think. 2003 was the year of the first "White Night" or La Notte Bianca in Rome. The city was staying open all night-- museums, restaurants, shops-- and a million people had taken to the streets to enjoy the festivities. I was outside my familiar amphitheater around 3am when the rain started. I was still standing outside when everything went dark. The White Night had turned into the Dark Night as the whole country lost power. You probably won't be able to create the blackout, but you can certainly visit one of the most awe-inspiring and unsettling places in Rome.