The Museum of London has secured £180m (US$224.4m, €208.7m) towards its £250m (US$311.7m, €289.9m) target to finance a move to the iconic Smithfield Market.

The City of London Corporation will contribute £110m (US$137.1m, €127.5m) to the scheme, with the Sadiq Khan pledging a further £70m (US$87.2m, €81.1m) – the largest cultural investment made by any London mayor in history.

The museum announced plans to relocate in March 2015, with management citing a number of problems at its current site including poor accessibility, an ageing building and a poor location.

Stanton Williams and Asif Khan triumphed over a number of architectural heavyweights in July last year, winning a competition with more than 70 entries to design the museum’s new home.

Williams and Khan will work together with conservation architect Julian Harrap and landscape design consultants J&L Gibbons on the project, which also will feature spiral escalators leading down to a vast excavated underground chamber, flexible meeting spaces, a sunken garden and green spaces.

The new museum, which will be constructed on the 25,000sq m (269,000sq ft) site, will retain many of the Victorian-era buildings, including Smithfield’s iconic dome structure.

Visitor figures at the Museum of London have more than doubled in recent years and continue to grow. The move is expected to create an additional 5,000sq ft (464.5sq m) of space, with the aim of reaching two million visitors per year.

The museum was given the green light to move to Smithfield Market in January 2016 after redevelopment plans for the historic site were abandoned. A planning application still needs to be submitted, with the museum presenting its designs to the City of London Corporation in 2018. An opening date has been set for 2022.