Vienna’s historic centre – a Unesco-designated site recognised for its Baroque castles, majestic parks and grand 19th-century Ringstrasse boulevard – has been placed on the United Nations (UN) body’s endangered list and could be at risk of losing its Unesco status because of a planned high-rise development.

Construction on a 6,500 sq-m complex, developed by the city’s Social Democratic and Green party coalition, is set to start in 2019 and will include a hotel and luxury apartments within a 66.3 metre-high tower – the height of which was reduced from 75 metres following opposition – as well as a conference venue, a 1,000 sq-m indoor skating rink, and open-air public areas that developers claim will enhance the city’s architecture with an “attractive and modern” feel, the AFP reports.

Maria-Theresien-Platz, the public square found at one end of Vienna's historic Ringstrasse boulevard Credit: AP

But Unesco's World Heritage Committee (WHC) believes the project “fails to comply fully with previous committee decisions, notably concerning the height of new constructions, which will impact adversely the outstanding universal value of the site”.

Unesco’s height restriction for any building in the city centre is set at 43 metres, but the coalition argues other post-war buildings in the area are of a similar height or taller than the proposed tower.

The Belvedere palace and garden is one of the centre's greatest Baroque structures Credit: AP

Local residents are also reportedly against the latest project, fearing it could cost the city its Unesco World Heritage status and encourage more high rise developments. But city officials say no similar projects are planned and claim they are dedicated to protecting its Unesco designation. The city reportedly has until February to convince the WHC not to remove its Unesco label.

The historic centre was awarded Unesco status back in 2001 for having “all the attributes that sustain its outstanding universal value, including its architectural and urban qualities and layout, and that illustrate its three major phases of development – medieval, Baroque, and the Gründerzeit – that symbolise Austrian and central European history,” the UN body describes, adding “the historic centre of Vienna has also maintained its characteristic skyline.”

Liverpool, one of 30 British World Heritage Sites, could also be stripped of its treasured Unesco status over plans to redevelop its historic waterfront Credit: Alamy

Unesco also warns the city’s “continuing development requires a very sensitive approach” that needs to keep in mind what makes the area so valuable, “including its visual qualities, particularly regarding new high-rise constructions”.

Of the 1,052 World Heritage sites across the globe, the historic centre of the Austrian capital is the 54th property to join the UN body’s list of sites in danger, for reasons ranging from war and civil unrest to poaching and urban encroachment. Two sites in Afghanistan are on the danger list, as are three in Iraq, five in Libya and six in Syria. Liverpool, one of 30 British World Heritage Sites, is also on the danger list and could be stripped of its treasured Unesco status over plans to redevelop the city's historic waterfront.

Meanwhile, Australia’s Great Barrier Reef was left out of the UN body's latest “in danger” list, a decision described as perplexing by scientists who said the condition of the coral and marine life was “worse than ever”.

The Great Barrier Reef was left out of Unesco's latest endangered list, despite concerns over the reef's recent mass bleaching events Credit: Maerie/Maerie

Despite expressing concern about the reef’s recent mass bleaching events, the WHC decided not to list the marine park as endangered – a move that would have been embarrassing for the federal government and could threaten tourism.

But Ethiopia’s Simien National Park and the Comoé National Park Ivory Coast were no longer deemed to be under threat. At the former, measures have been made to reduce cattle overgrazing and visitor impact, while work has been done to stop poaching at the latter, with targets for fauna conservation surpassed.