The new Thames cable car, spanning the river, has opened to the public.
The Emirates Air Line links the O2 Arena in Greenwich, south-east London, with the ExCel exhibition centre at the Royal Docks in east London.
The service can carry 2,500 people an hour, Transport for London (TfL) said.
A single adult fare on the pay-as-you-go Oyster card will cost £3.20 while the cash fare is £4.30. But the fares are not included in travelcards or Oyster capping, TfL said.
The service will operate through the week from 07:00 until 21:00.
The gates will open an hour later on Saturdays while the service will run from 09:00 on Sundays.
Passengers will also be able to make a non-stop round trip on the cable car, with views of the City, Canary Wharf, the Thames Barrier and the Olympic Park, at a cost of £6.40 with Oyster.
But Transport for London said a one-way journey at peak time will be between four and five minutes long, but off-peak the same journey will last about 10 minutes.
The Dubai-based airline Emirates is sponsoring the cable car for 10 years at a cost of £36m.
The total cost of the project is about £60m, £45m of which went towards building it, TfL said.
Mayor of London Boris Johnson called it a "stunning addition to London's transport network" and a "must-see destination in its own right".
He continued: "We said we could deliver this travel link in quick time, and today we have shown that this city is capable of attracting serious investment to deliver world class infrastructure.
"As the world's eyes focus on our city, I can think of no better message to send out across the globe."
Sharon Grant, chair of TravelWatch, said: "We have been supportive, but we are very watchful about the funding."
She added that although the scheme had been broadly privately funded, it remains to be seen whether the fares can cover all the costs or if the public purse would be left to pick up the pieces.