The Newport Transporter Bridge will get a new visitor centre as part of a £12m masterplan to safeguard its future - if flooding fears can be allayed.
A virtual recreation of the view and wind at the top of the Grade I-listed bridge will be offered to visitors who cannot climb the 277 steps to the top.
Natural Resources Wales has objected, calling for more detail on how flood risks can be managed.
But city councillors will back the plan once that issue has been addressed.
The structure, which opened in 1906, is one of only two working transporter bridges remaining in the UK, and one of only six worldwide.
It carries vehicles and foot passengers across the River Usk in a gondola suspended from the top.
City councillors backed the plans after hearing the current visitor centre can only comfortably accommodate four people at a time and has just one accessible toilet.
The proposals will see it replaced by a bigger, modern building, which also reflects the area's industrial history and architecture, according to the Local Democracy Reporting Service.
It is hoped the project will more than double visitor numbers to the site, which are currently 16-20,000 a year.
Councillor John Guy said the plans were a "celebration" of the bridge and he hoped it would "become one of the seven wonders of the world".
Another councillor, Val Dudley, also spoke in support but said she would have liked the designs of the visitor centre to be "a little bit softer" to make it more in keeping with the historic structure.
Repairs and restoration work to extend the operational life of the bridge by 25 to 30 years are also proposed as part of a separate application to Welsh Government and its historical landscape arm Cadw.