WATCH: Singapore airport nature dome unveiled in fight for flights

SINGAPORE, Singapore — A 40-meter indoor waterfall cascading through a steel and glass dome is at the heart of a vast complex in Singapore's main airport unveiled Thursday, part of the city-state's fight for global flights.

Reportedly built for a cool SG$1.7 billion ($1.25 billion), the "Jewel" center has gardens growing over four storeys, as well as 280 retail and food outlets, a hotel and cinema. It links to three of the airport's terminals.

But analysts were sceptical the 135,700 square meter (1.4 million square feet) complex would be a hit with transiting passengers -- immigration has to be cleared to reach it and Changi airport already has high standard facilities.

As well as an attraction for visitors to Singapore, it is also billed as a destination in its own right for local residents. 

Jewel started welcoming a limited number of visitors this week, and will open fully to the public next Wednesday.

It is part of efforts by Changi -- the world's seventh busiest airport for international traffic -- to attract long-haul travellers over other hubs such as Hong Kong and Dubai.

"Passengers are spending a longer time as they transit through airports, which is the reason why there is a need for us to increase the amenities," said Jayson Goh, a senior executive at Changi Airport Group.

But Brendan Sobie, chief analyst at the Center for Asia Pacific Aviation, said that Jewel would "primarily be used by local residents and some departing passengers". 

"Attracting transit passengers is not realistic as they would need to clear immigration and there are so many great facilities (inside the airport) already that makes Changi a top transit airport," he said.