Demolition work at a former landmark Hull department store has revealed a mosaic hidden from view for decades.
The disused BHS building also has the larger Three Ships design on the front and is being demolished in the Albion Square regeneration.
The fish artwork hand-made by Alan Boyson, who designed three murals in the building, has been exposed by demolition of a corridor.
The fish were covered up in the 1970s when a ballroom became a nightclub.
The 1961 work features 16 ceramic fish swimming in a sea of marble and terrazzo seaweed on the fourth floor.
It was originally to be a decoration for a rooftop balcony outside the Skyline Ballroom, but the balcony became a corridor.
The mural was then boxed in when the building's ballroom became Bailey's nightclub. It was rediscovered in 2011 but could not then be seen as the nightclub had closed.
Hull City Council gave the chance for drone footage to capture the mural.
The footage is to be used in Ships in the Sky, an oral history film and exhibition looking at the effects of the building on local identity, set to be released in 2020.
The Three Ships comprises almost a million pieces of Italian glass on a 66ft by 64ft (20m x 19.5m) concrete screen and commissioned for its store by the Co-Op in 1963 paying tribute to Hull's fishing heritage.
A third geometric sponge print mural by Boyson remains inside the building.
The council has said it intends to save the works but has not yet outlined how it intends to do so.