No people

This is the interior of the Natural History Museum in London. All of the museums in this city are free, and that means they are constantly crowded. So, how did I get a picture like this with no people? I arrived at the ticket office one hour before they opened when no one was there. By opening time at 10am, there were probably 200 people in line behind me. As soon as the gate opened, I went through a brief security check (because I had a camera backpack) and then rushed to the vantage point you see here. I had scouted the museum the day before, so I knew exactly the location from where I wanted to shoot. No tripods are allowed in the museum, of course, so I rested my camera and 14mm lens between the two railings you see in the foreground. I had to use a small lens to prevent the railings from becoming distractingly out of focus. I used the 2-second self-timer in lieu of a cable release. This is a 3-frame HDR composite. Within 5 or 6 minutes of taking this shot, two or three people were standing on the balcony at the bottom of the stairs. Within 10 to 12 minutes, there were probably 10 people on that balcony, making further photography impossible. My settings were 1/5 seconds, f/22, 800 ISO.