Standing as a startling collection of futuristic Italian architecture from the 1930s, perched on a desert mountaintop high above the Red Sea, the Eritrean capital of Asmara has been listed as a Unesco world heritage site.

Announced as one of a series of new “inscriptions”, which are expected to include German caves with ice-age art and the English Lake District, Asmara is the first modernist city in the world to be listed in its entirety.

First planned in the 1910s by the Italian architect-engineer Odoardo Cavagnari, Asmara was lavishly furnished with new buildings after Mussolini’s invasion of Ethiopia in 1935, when the sleepy colonial town was transformed into Africa’s most modern metropolis. As the “little Rome” at the centre of Italy’s planned African empire, it became a playground for Italian architects to experiment.

Facebook Twitter Pinterest The Asmara Theatre. Photograph: AFP/Getty Images

“It has an unparalleled collection of buildings that show the variety of styles of the period,” said Edward Denison, a lecturer at UCL’s Bartlett School of Architecture, who has been working as an adviser to the Asmara Heritage Project, helping to put together the 1,300-page bid document, the result of two decades of research. “You get a sense that the architects were getting away with things here that they certainly wouldn’t have been able to do in Rome.”

From the daring cantilevered wings of the Fiat Tagliero service station, modelled on a soaring aeroplane, to the sumptuous surrounds of the Impero cinema, the city is full of buildings that combine Italian futurist motifs with local methods of construction.

Facebook Twitter Pinterest Fiat’s Tagliero garage, a petrol station with 60ft concrete wings mimicking an aeroplane taking off Photograph: Peter Martell/AFP/Getty Images

Behind the sharp cubic facades stand walls of large laterite stone blocks, carefully rendered to look like modernist concrete constructions, finished in shades of ochre, brown, pale blue and green – much more colourful than their European counterparts.

Some buildings, such as the Orthodox cathedral, have a bold hybrid style, with African “monkey head” details of wooden dowels poking through the facade, originally used to to bind horizontal layers of wood together between the blocks of stone.

Facebook Twitter Pinterest Orthodox cathedral in Asmara. Photograph: Radu Sigheti/Reuters

Elsewhere, there are handsome villas, stylish shops and heroic factory complexes, sampling from modernism’s broad palette, including novecento, rationalism and futurism, most of which remain in an unusually well-preserved state.

“While other countries like Libya and Somalia were understandably keen to trash their colonial heritage,” said Denison, “Eritrea was subject to a decade of British rule and 40 years of Ethiopian rule, so the process was more gradual.”

When independence finally came in the 1990s, a sudden rash of modern buildings made many realise the value of their colonial heritage.

Facebook Twitter Pinterest The central mosque. Photograph: James Baigrie/Getty Images

A moratorium on building in the city was established in 2001, which is now planned to be lifted with the introduction of a new conservation management plan, updating the regulations for the first time since the 1930s.

The inscription of Asmara – along with historical centre of M’banza Kongo in Angola – goes some way to addressing the under-representation of Africa on the Unesco world heritage list. Of 814 cultural sites worldwide, only 48 are in the African continent, fewer than in Italy alone.

