Trademarks must be distinctive. This requirement is often in contrast with the aim of marketers to inform consumers in a simple way about the qualities of a product. Comfortchair, Smartcar and Doublecheese burger are descriptive brands for a chair, car and a hamburger. Maybe good brands from a marketing point of view, in trademark law perspective not the strong trademarks you wish to register. The difficulties of registering these trademarks can be avoided by adding graphical elements, however, the tendency is that the acceptance of descriptive words with graphical elements is becoming more difficult as well.
Geographical indications have a special place in the category of descriptive trademarks. In principle, a geographical indication says something about the origin of a product. Unless the place is very small or when it is not to be expected that the products in question will come from this place. Antarctica, for example, is a good trademark for computers, but Shanghai would not be accepted as a trademark.
Some trademarks have historically been formed by a certain place. Take Wembley, the historic stadium in London. The name Wembley comes from the district where the stadium is located. Wembley recently filed the wordmark WEMBLEY in the European Union but this trademark was refused by the EUIPO for services in class 41 such as events. The reasoning was that this name directly informs the public that the events are taking place in the Wembley district. Wembley appealed the decision and with success: the Boards of Appeal took a different view as they found that it is not very likely that the relevant public will think of anything else than the stadium.