It may be hard to believe now, but San Francisco was once dominated by railways. Before private cars crowded this hemmed-in city, rail was the only way to get around the challenging terrain, and the rail industry rose to the task with many innovative systems. Some of these were herculean, with massive bores through rocky hills, or elaborate cable and counterweight systems to handle steep inclines. Others were simpler, horse-drawn affairs that took passengers from the downtown and waterfront areas to outlying districts. The distinct flavor of San Francisco's neighborhoods owes much to the early rails, as these cars enabled residents to form their own enclaves and still interact with the commercial heart of the city. Some rail systems presaged today's commuter lifestyle-one even ran all the way down Mission Street to far-off San Mateo. Only a few of the many rail systems that once served this city remain.