In contrast with the low-rise historic areas, the business district on Si Lom and Sathon Roads in Bang Rak and Sathon Districts teems with skyscrapers. It is the site of many of the country's major corporate headquarters, but also of some of the city's red-light districts. The Siam and Ratchaprasong areas in Pathum Wan are home to some of the largest shopping malls in Southeast Asia. Numerous retail outlets and hotels also stretch along Sukhumvit Road leading southeast through Watthana and Khlong Toei Districts. More office towers line the streets branching off Sukhumvit, especially Asok Montri, while upmarket housing is found in many of its ''soi''s ('alley' or 'lane').