SoMa ("South of Market") and the Financial District are distinct neighborhoods with their own distinguishing characteristics, and aren't actually adjacent -- they're essentially kitty-corner from one another along Market Street, a central artery that cuts through the center of downtown San Francisco. So why group them together? They share a business-centric atmosphere, attract a large portion of the city's business travelers between them, and are about equidistant from many of the city's most popular tourist attractions.
Full of well-tailored suits and skyscrapers, the Financial District is wedged between downtown San Francisco and the waterfront; and borders the Embarcadero, Chinatown, Union Square, and Market Street. It's not particularly convenient to many of the city's biggest tourist attractions -- it's about as far from Golden Gate Bridge and Park as you can get, for example -- but that's true of most of San Francisco's hotel-heavy areas.
SoMa, "South of Market," has cleaned up and grown considerably in the past 10 years or so, coming into itself as a business district with an artistic bent -- some of the city's best museums are located within these blocks. The result is artistically landscaped office buildings with a small selection of bars and restaurants that attract a decidedly business crowd.
On weekends and weekday evenings, SoMa and the Financial District are both all but dead. A few notable restaurants, like Anchor & Hope and Tres Agaves, and the city's pioneering transgender restaurant and club, Asia SF, dot the neighborhoods, but these areas are mostly filled with chain restaurants, Starbucks, corporate skyscrapers, and business hotels.
SoMa and the Financial District both have their share of 600-plus-room hotels like the Marriott, Hyatt, and Westin. But some of the city's luxury properties are also here, including the St. Regis and Four Seasons, both just South of Market, and the Mandarin Oriental in the Financial District. With the exception of Good Hotel, an environmentally conscious boutique on the outskirts of SoMa, the area's hotels start at or above $200 a night -- so travelers on a tight budget, or anyone seeking a funky urban boutique, should look elsewhere.