Your ride is aboard a double-decker bus with a transparent sliding roof, so you can see the sights without getting rained on, or cold or sunburned; the two-hour tour includes photo ops of 40 Paris monuments, and the full-day hop-on, hop-off option makes eight stops. Buy your ticket online, on the bus, or at one of the three main departure points: the Palais Garnier opera house, the Louvre or Notre Dame.