Ahead of the capital's flagship marathon on Sunday, BBC London handed disposable cameras to two runners to capture the highs, lows and overall experience of the day.
Cameron Crabb, from Battersea in south-west London, and Sian Kearney, from Felsted in Essex, took up the task of recording their race day on old-school film.
Both runners took on the 45th edition of the London Marathon to raise funds for charities personal to them.
Cameron, 25, ran the 26.2 miles (42.2km) in memory of his mother, Gill Crabb, who died unexpectedly aged 51.
While 20-year-old Sian took on her first marathon in memory of her uncle James, who died from muscular dystrophy when she was a toddler.
A keen film photography enthusiast, Sian said she initially set out to capture landmarks and charity spots.
"But really looking back on the pictures, I think I genuinely captured the whole emotion of the whole day," she said.
Cameron was running in aid of a foundation he set up in his mum's name to teach underprivileged children how to cook nutritious meals. He said it was a dream she had planned for her retirement.
Waking up on race day at his brother's home in Greenwich, Cameron said he felt "very excited" but "a little bit apprehensive" about the warm weather.
He wanted to use the disposable camera to capture "some of the sights along the way" and document moments many people would not usually see, such as inside the starting pens.
Cameron said he also looked out for "funny or cool costumes", snapping photos of runners dressed in a variety of outfits.
"It was actually quite emotional," he said about the crowds cheering runners on.
"The whole 26 miles, you've got people two or three deep on each side of the road, cheering people on who they have no idea who they are, but they're sort of just there to support."
Cameron completed the course in just over four hours, raising more than £2,500 for the Gill Crabb Foundation, which now supports some 30 schools across the UK.
Running for Muscular Dystrophy UK, Sian crossed the finish line carrying a teddy bear her uncle had given her as a baby, which her parents handed to her just before the final stretch.
"It gave me that little boost that I needed to drag myself over that finish line," she said.
She said looking at the photos, they capture all of the emotions she went through during those 26.2 miles.
In some of the pictures she is a "bit more teary", she said, while in others, her "smile is so big, and I'm so excited and happy about everything that was going on".
While many runners spoke about the crowds spurring them on, Sian, who achieved a time of six hours and 57 minutes, said she found parts of the race overwhelming, including the number of spectators – despite their initial boost in the race.
"In moments where I shut down a bit and was struggling, the crowds actually made me feel more anxious," she said.
"But I learned so much about myself – I know now that I have more internal motivation than I realised."
Sian encouraged others to take part in the London Marathon, even if they felt apprehensive about the challenge.
"Your mind can do brilliant, brilliant things when you have that motivation," she said.
