A 25,000-seat arena is being proposed for the Olympic Park. Here's what we know.

Plans have been unveiled for a major new indoor arena in Stratford - and if it gets built, it would be the largest indoor venue in the UK.

The project, called the London Colosseum, is being developed by Jericho Estates, Peacock Gym, Torch Sports, and architects Chybik + Kristof. The proposed site is in Queen Elizabeth Olympic Park, close to the stadium now home to West Ham United.

At 25,000 seats, it would overtake Manchester's Co-op Live (23,500 capacity) and the O2 Arena (20,000 capacity) as the UK's biggest indoor venue.

What's being planned

The arena's bowl design is intended to flex between 18,000 and 25,000 spectators, depending on the event, with the developers positioning it as a genuine multi-use venue rather than a single-purpose stadium.

Alongside the main arena, plans include a mixed-use tower with hotel rooms, residential apartments, and community spaces - designed to keep the site active outside of event days.

A second site within the development, called the London Colosseum Academy, would feature two smaller 3,000-seat venues, a basketball school, Peacock Boxing Gym & Academy, and an international esports training centre.

What could it host

The developers are pitching it as a potential home for world championship boxing, UFC events, international esports, and a future London franchise in the NBA's planned European competition, expected to launch in 2027 or 2028. The O2 has already hosted NBA basketball this year - Orlando Magic vs Memphis Grizzlies - so the London Colosseum would be entering a market where a well-established competitor already has a head start.

It also remains unclear whether this proposal is connected to the separate 20,000-capacity basketball arena project backed by the London Lions and Mayor Sadiq Khan. These could be two competing bids for similar ground - or they could be entirely unrelated. Nobody has said.

Reasons to be sceptical

The NBA Europe league this venue is partly built around is not a done deal. Talks between the NBA and EuroLeague are reported to be at an impasse, adding uncertainty to the whole bidding process. There are also already competing bids for the London franchise, including one from the owners of Formula E.

There's also local precedent for ambitious arena plans not making it through planning. A proposal for a large sphere - similar to the MSG Sphere in Las Vegas - in another part of Stratford was previously refused at the planning stage.

Where it actually stands

The designs have only just been made public and the planning process is in its early stages. No construction timeline has been released.

East Village is already living next to a major stadium, a velodrome, and an aquatics centre. The neighbourhood has form for absorbing world-class infrastructure. Whether the London Colosseum joins that list is a different question - and right now, it's still very much just a question.