Smithfield market will be the museum’s new home, but which architectural vision should shape its future: the eye-catching one, the ghostly one, the corporate one … or the one that rings alarm bells?

Marooned on a grim roundabout in the City of London since the 1970s, cloistered away behind forbidding grey walls, the Museum of London is finally making a bid for freedom. Six shortlisted designs have been unveiled for its new home in Smithfield, where it hopes to breathe much needed life into three derelict Victorian market buildings to the west of the thriving meat market, with a project set to open by 2021.

Developers and conservationists have long waged war over the future of the 25,000 square metre site, which includes the majestic iron-framed hall of the general market, along with the former Fish Market and a cold store known as the Red House – as well as a working underground rail line that the museum hopes to incorporate into its plans.

The buildings were saved from evisceration by a bloated commercial development in 2014. The challenge is now how to insert a museum that boasts the largest urban history collection in the world (and wants to double its visitors to 2m a year) without destroying the magic of the place.

Little detail has been revealed about the shortlisted schemes, which will go on public exhibition from 10 June to 5 August with a winner chosen by an expert panel later this summer.