Every year, over 100,000 people attend the Comic Con in London to see their favourite actors, directors and artists in the sci-fi, fantasy and manga world, as well as buying memorabilia.
But the convention is the most famous for people of all ages showcasing their most incredible cosplay outfits, or role-playing costumes.
Some are incredibly elaborate and would cost thousands of pounds to create, while some are more simple but incredibly stunning.
The idea is to escape from reality for just one day and pay homage to their favourite TV programmes, movies, comics and popular culture characters.
Business Insider attended the event and here are some of our favourite cosplay outfits.
People of all ages turn up in the thousands dressed as their favourite characters, and manga -- comics created in Japan -- gave birth to the most popular cosplay ideas.
Many people dress as 'kawaii,' which is a term used in Japanese culture to denote the quality of cuteness. Here are three friends from 'Love Live! School Idol Festival.'
The manga characters range from the adorable to the deadly. A lot of friends would dress as complementary characters from the same series
Characters from Western animated movies also heavily feature, such as Elsa and Hans from Disney's huge blockbuster 'Frozen.'
But war and action film and computer game related characters were massively popular and incredibly intricate. These soldier costumes from the computer game 'Fallout' were heavy duty and the masks even had a voice-altering communications panel inside.
Some cosplay outfits could've been lifted straight from the films. One guy had a War Machine costume from the Marvel series 'Iron Man.'
And here is a storm trooper, Kylo Ren, and famous starfighter lookalike from 'Star Wars: A Force Awakens' Poe Dameron.
Some people meshed their favourite characters into a unique concoction. On the left, someone melded Darth Vader into a 'Space Marines' soldier while a girl on the left combined Harley Quinn with a 'Space Marines' soldier -- both creating over 8 feet high cosplay outfits.
Some kept their armour more old-school and created characters from the 'World of Warcraft' computer games.
Here are two characters from the 'World of Warcraft' computer game standing by the huge pod where Universal Pictures was showing the trailer for the movie adaptation, which is out now.
Computer games are a great birth ground for some seriously elaborate costumes. Here someone is dressed as a motorised-patriot -- a automation that tries to kill you in the game 'Bioshock Infinite.'
But classic sci-fi and fantasy films are also popular with the older cosplayer. Here is a family dressed as Predators from the movie and comic book series.
This year, steampunk -- a subgenre of science fiction that incorporates Victoriana and technology that is steam powered and mechanised -- had a huge turnout.
Steampunk has been growing as a sci-fi genre over the last few years and every year there is a huge festival in Lincoln, north England.
Most steampunk cosplayers have items that 'work.' So for example, this guy's contraption moved, made noises and looked and felt like a real-life steam powered pack on his back.
But some of the best outfits keep it incredibly simple. This guy, who was struggling a bit with walking, dressed as Baymax from Disney's 'Big Hero 6.'
Sometimes the outfits that got the most laughs and pictures were ones that were an in-joke. Here this guy is from a scene from the incredibly popular anime series 'Attack on Titan.' He is one of the monsters -- Titans -- that penetrates a security wall in the series called Wall Rose.
Some people kept it simple from classic cartoons so the whole group of friends could all match. Here, a group dressed as the gang from the 1960s cartoon 'Scooby Doo.'
Business Insider Emails & Alerts
Site highlights each day to your inbox.