Merlin Entertainments is planning to open a 5,500 sq m Lego Discovery Centre at the Barclaycard Arena in Birmingham, with the creation of up to 50 jobs.
A 4D cinema, rides, and games are among the attractions planned for the site, as well as a cafe.
According to the planning application, Merlin estimates that at the busiest times of year up to 2,500 children will attend for an average two hour visit between 10am and 6pm.
There is only one other Legoland Discovery Centre in the UK - which opened at the Trafford Centre in Greater Manchester in 2010 - alongside a Legoland Resort in Windsor and other venues across the world.