Despite the storied hills of San Francisco, you will see many cyclists here of both the casual and racing variety. Because the city has made cycling a priority in city planning, there are plenty of bike lanes and trails to suit every fitness level: flat routes tend to be by the water, but if you're looking for a challenge there are lots of those too, many with excellent views once you reach the summit. Rentals are available from the city-wide Bay Area Bikeshare, but you can also book a cycling tour with several reputable companies.