The actor took on the role of the superhero in Tim Burton's 1989 movie and he jetted to the British capital to shoot the picture at the famous Pinewood Studios.
Keaton admits he loathed the location and was constantly miserable during filming because he had separated from his wife Caroline McWilliams and was desperate to spend time with his young son, Sean.
He suffered from insomnia and rarely socialised with other people as his problems seemed to intensify during the "difficult" shoot.
He tells the Los Angeles Times, "It was a lonely time for me, which was great for the character, I suppose. I would run at night in London just trying to get tired enough so I could sleep. I didn’t talk to people much. My little boy was a toddler, and the woman I was married to at the time, we were not together but we were trying to figure it out and get back together.
"It was me in London, alone, and my sleep during that whole movie was never right. As often as I could, I was getting on the Concorde and trying to get back to spend some time with my kid.
“It was an extremely difficult undertaking... and there was so much pressure. We were in England for a long time shooting at Pinewood and it was long, difficult nights in that dank, dark, cold place, and we never knew if it was really working."
McWilliams, who was married to Keaton for eight years, died at her home in Los Angeles on 11 February (10), aged 64.
Her TV credits include recurring roles on U.S. soap operas Guiding Light and Another World, Beverly Hills, 90210, and late 1980s comedy, Benson.
She also featured in 1990 movie Mermaids, starring Cher and Winona Ryder.
Keaton and McWilliams divorced in 1990. She is survived by their son Sean Douglas, 26.