There are currently two separate schemes in the pipeline to develop the abandoned Victorian structures, which are located barely a mile apart in Holbeck and which were built during the Victorian railway boom.
They'd see the old viaducts, which once carried railway lines into the city, become walking and cycling routes with bars, shops and community spaces.
One scheme has been proposed by a property developer while the other is community-led.
Holbeck Viaduct Project
A campaign group was set up in 2013 to bring the Holbeck Viaduct back into use. Nicknamed the Holbeck Highline, its backers want the scheme to be a reality by 2023. Their vision would include green space, a walkway, allotments, community arts space, play areas and a market. They've been in discussions with Network Rail, who still own the structure, about the possibility of re-opening it.
The London North Western Railway built the viaduct in 1882 to bypass the congested lines leading to the present-day Leeds Station. Their new line from Huddersfield branched off at Farnley & Wortley before heading into the city via Beeston and Holbeck. Nowadays, it ends at Granary Wharf, and the structure crosses Globe Road. It runs close to Elland Road, meaning it would be an ideal route for Leeds United fans to travel to matches from the city centre.
It's 1,500 yards long and has 82 arches. The track remains on one side of a gate erected by Network Rail. Trains stopped running on the line in 1988, but the viaduct was used as an emergency 'holding' line for trains during incidents of service disruption up until the 1990s.
Monk Bridge Viaduct scheme
The remains of the much shorter Monk Bridge Viaduct run parallel to Whitehall Road on the other side of Holbeck. It was originally built as an access route into the old Leeds Central Station, which stood on the site of the Wellington Place office development, and carried the railway over both the River Aire and the Leeds and Liverpool Canal. It was the same railway company, the London North Western, who built it in 1846. The station itself closed in the 1960s, when the last train ran over the viaduct. It has been abandoned ever since, and when iron and steelworks Doncaster Monk Bridge took over the site the structure remained on their land.
It now forms part of another ambitious 'skyline' project, this time led by developers BAM Monk Bridge. The plans are fairly similar - the old trackbed would become a greenway and pedestrian path. The viaduct itself was severed after its closure, so it no longer reaches as far as the old station site. The archways beneath it would be home to bars, restaurants and shops.
They've also cited New York's High Line as their inspiration. Leeds City Council approved the scheme in 2017, and preparatory surveying work has begun, but building hasn't started yet. A high-rise residential and office scheme to be developed alongside the viaduct was granted planning permission earlier this year.
The viaduct featured in the BBC's adaptation of Agatha Christie's novel The ABC Murders last Christmas. Extras in police uniforms appeared under the arches and a CGI steam train was superimposed onto the old line.