• Chinta Ria closes at Westfield Sydney

The CBD's newest urban oasis will open this week with a rumoured sky-high spend of $20 million.

Not that they are shouting it from the rooftops (in case you haven't guessed, it's a rooftop venue).

Arj Rupesinghe​ from Mantle Group dodged questions about the price tag but agreed the build came with its challenges.

They had to crane in many building materials and most of the furniture, and a new escalator was installed to ferry customers faster from street level.

Licensed for 1400, with two restaurants and bars, it's one of the boldest hospitality plays in Sydney this year.

Rupesinghe says the Westfield Sydney site ticked many of the boxes for successful rooftops around the world.

"Rooftop venues in busy CBDs are somewhere to get out of the office and the air-conditioning. It isn't too high up, which is important, so it's less windy and a little more sheltered. Plus the views looking out are great," he says.

If it sounds like a bigger project than the Hanging Gardens of Babylon, the venue has the bar-restaurant to match, with Babylon tapping a Levantine-inspired menu with chef Arman Uz (Efendy, Jaaks) in the kitchen and David Nutting (Hubert, Eau de Vie) behind its nine-metre dark gold Spanish marble-topped bar.

More than 300 handmade iron lanterns decorate modern Cantonese restaurant, Duck & Rice.

After menu testing, does Rupesinghe have a favourite? "I am partial to duck, but Babylon has some amazing dishes. It'll take me a few weeks to make up my mind."

Babylon open daily 10am-midnight; Duck & Rice open daily 11am-midnight.

Babylon and Duck & Rice, Level 7, Westfield Pitt Street, Sydney. Enter via express escalator from Pitt Street Mall or for direct lift access, enter via Castlereagh Street adjacent to Cerrone and take lift to Level 7.

Babylon: 02 9023 9990, babylonrooftop.com.au.

Duck & Rice: 02 9023 9991, duckandrice.com.au