The cheapest way to see Paris is on foot .It's the best way to enjoy the street life of ereas like Montmartre, the Latin quarter or the Bois de Boulogne .But , as in any big city , you should be careful at night in certain areas.
The Metro - Paris 's underground system , the second largest in Europe- is the quickest way to get around . it's open from 5:30 a.m.-12:45 a.m. . Tickers cost 1.40 or you can buy a book for ten tickers for 10.50