Bangkok lacks a single distinct central business district. Instead, the areas of Siam and Ratchaprasong serve as a "central shopping district" containing many of the bigger malls and commercial areas in the city, as well as Siam Station, the only transfer point between the city's two elevated train lines. The Victory Monument in Ratchathewi District is among its most important road junctions, serving over 100 bus lines as well as an elevated train station. From the monument, Phahonyothin and Ratchawithi / Din Daeng Roads respectively run north and east linking to major residential areas. Most of the high-density development areas are within the  area encircled by the Ratchadaphisek inner ring road. Ratchadaphisek is lined with businesses and retail outlets, and office buildings also cluster around Ratchayothin Intersection in Chatuchak District to the north. Farther from the city centre, most areas are primarily mid- or low-density residential. The Thonburi side of the city is less developed, with fewer high rises. With the exception of a few secondary urban centres, Thonburi, in the same manner as the outlying eastern districts, consists mostly of residential and rural areas.