Stretching into blue skies far above other towers crowding the Spanish resort of Benidorm, the Intempo skyscraper stands as a hard-to-miss beacon of excess from the days of Spain's property bubble.

Floor numbers flash by on a blue screen as a new elevator soars up this 180-metre (590-foot) giant on the skyline of Benidorm, a mass tourism resort on eastern Spain's Mediterranean coast.

At the foot of the 54-floor building -- touted as the highest residential skyscraper in Europe -- a semi-Olympic swimming pool waits to be tiled before welcoming the 1,000 residents who developers hope to lure to its apartments.

The building's twin towers are covered in copper-coloured windows and joined at their summit by a vast inverted pyramid, its concrete facade still open to the elements.

Soon, the concrete floors and bare wires will be transformed into two 300-square-metre luxury duplex penthouse apartments, their glass walls overlooking several kilometres of beach on one side and hinterland on the other.

"You see, there is no reason for controversy: there are 11 elevators," said Guillermo Campos, technical architect of the building's property developer Olga Urbana, who is determined to rebuff newspaper articles saying the builders forgot one elevator shaft.

Campos rejected concerns by Greenpeace Spain and others about the environmental impact of concentrating so many people in a single building.

"Look at that clean water," he said, pointing to a beach from the giddy heights of the Intempo.

Far below, Spanish, British, French and German tourists walked along the beach's new promenade.

Some 35 percent of the building's apartments have been sold, Campos said, a relatively small proportion with so little time before its scheduled delivery in early 2014.

Hoping for a property market recovery from mid-2014, Campos said he was counting on interest from Russian, Algerian and British buyers despite prices that appear lofty: from 350,000 euros ($473,000) for a studio to three million euros for a duplex.

A tough sell?

Launched in 2007 in the dying days of Spain's property bubble, which imploded the following year with devastating economic consequences, the skyscraper's construction has been hit by public disputes with the builders who are demanding a million euros ($1.3 million) in unpaid bills from the promoters.

The loan that financed construction was transferred last year to Spain's "bad bank", Sareb, set up to pool the financial industry's toxic assets as part of a European Union-financed banking sector rescue for Spain.

Caixa Galicia, the bank that extended the original loan, has since been rescued by the state. As a result, it was obliged to discount the price of some assets and property loans on its books and move them to Sareb.

A spokeswoman for Sareb said the fact that it had taken over the Caixa Galicia loans did not mean their repayment was considered to be doubtful.

Nevertheless, the association of Intempo with Sareb, a symbol of the property market collapse, can only complicate the titanic task of selling 269 luxury apartments in a stagnant market.

Benidorm's city hall shows little concern, however.

"It does not matter" if it takes a little longer to fill the building, said the city hall's chief architect, Jose Luis Camarasa.

"Here, the city development has been following a plan conceived 50 years ago," he said, arguing that this had allowed Benidorm to avoid the pitfalls of the property boom.

"What Benidorm built in 50 years -- 30,000 homes -- some cities built in a single year," he said.

A fishing village five decades ago, Benidorm today is a mass of skyscrapers, fast-food outlets, bars and nightclubs where tourists, mostly northern Europeans, come on cheap package holidays.

The first city development plan was drawn up in 1955, then modified in 1963 to scrap height limits on towers so as to "democratise tourism", Camarasa said.

Prices "will probably have to come into line with the market", Camarasa admitted. But for the property market in Spain's eastern Valencia region, "Benidorm is the jewel in the crown", he said.