Saladaeng Skytrain and Silom Subway stations area.
The Silom - Saladaeng area is one of three places where the SkyTrain and Subway systems cross. The area used to be Bangkok's main business district, until growth and traffic forced many companies to move their headquaters to the suburbs. However, there still are a lot of corporate offices in the area.
The Dusit Thani is still the grand old dame of Bangkok hotels. A very short walk from the intersection along Rama IV road is the Pan Pacific Hotel, much newer and very business oriented.
Lumpini Park is easily accessed from this area. It is a popular place for exercising, with lots of options for jogging, aerobics, cycling or even weight training. "Entertainment" of an entirely different sort is just a short distance down Silom road from the Skytrain station. Patpong is Bangkok's long-time notorious red-light district, and also the site of a famous night market infamous for knock-off merchandise.
Silom Complex is the area's only shopping center, with a Central Department Store, several small shops and restaurants. The mall doesn't have anything of special interest. It mainly serves people who happen to work in the area or be there on business.