Why is a bar called a bar? Why should a room for eating or drinking in be called the same as a horizontal metal or wooden pole? And inbetween, the counter (pult) where the food or drink and the money change hands is also called the bar. So you can sit BY the bar on a bar-stool, or you can buy things AT the bar and take them to a table elsewhere IN the bar.

Which is your favorite downtown bar? This is an example of a common figure of speech called synecdoche/synekdoki/, where the name of part of something is used to represent the whole of it. The horizontal metal bar running along the top edge ot the counter, and another one running along it about 30 cm above the floor (making standing at the bar more comfortable by resting one foot upon it), made people call the counter "the bar", and then the counter as the main feature of the room encouraged people to call the whole room "the bar"