MBK Center or MahBoonKrong is a big shopping mall in PathumWan district. This shopping mall is well-known among tourists. When I was there, I always saw many tourists enjoy shopping and eating in the mall.
This shopping mall offers you both international and local products. The most popular products at this mall is mobile phone and accessories. Many locals go to this mall to buy/ sell second-hand phone. Besides, the mall has food courts and several restaurants. You can read my review of MBK here.
In order to go to MBK by BTS, it is very easy because MBK connects with BTS at National Stadium BTS Station which is the terminal station of Silom line. If you take the BTS on Sukhumvit line, you have to change the train at Siam BTS Station.
Besides, MBK is not far from Siam BTS Station. If you are in that area, you can walk to MBK.