Anyone visiting Paris for this summer's Olympic Games may have to pay a little more than usual for hotels, trains and food and drink. But here's one thing that won't cost them anything: a ride in a flying taxi. That's right: it might sound like the most expensive way to get around, but it has been announced that visitors will be able to take new electric-powered flying taxis without paying. They're called flying taxis, but if you're hoping for a car with wings you might be disappointed! They look like small helicopters, but with a "loop" on top with 18 small rotors instead of one large set of blades. In Paris, they can land on a special "vertiport" — a place for vertical takeoff and landing — on the River Seine. Made by a German company called Volocopter, the taxis can take one person at a time from the Seine, close to Austerlitz train station, to four places around Paris, including two airports. The trips are free because the flights are being called "demonstrations" — since the taxis have not yet been certified by the European Union's Aviation Safety Agency. There is also a limit of two flights per hour between 8 a.m. and 5 p.m, and a limit of 900 flights over the whole year. This has been called a "trial period" for the taxis, but some people in Paris are unhappy that they're coming at all. They're worried about the taxis' environmental impact, and the noise they might make. Volocopter says its taxis are much quieter than normal helicopters, as well as being very safe and better for the planet. In future, the company hopes to make larger taxis that could also be used as flying ambulances.