Once upon a time, centuries ago, it was an animal pen. It has also been a cellar, and more recently a bedroom. Now it is a lhakhang. A close translation for this would be “god-house”, so possible English equivalents would be shrine room, chapel or oratory. In any event, it’s the place where you have your most meaningful images, make offerings, do your daily chance and perform some of your meditation practice.
It is almost as quiet as the grave, although I do sometimes hear the neighbour going past up and down to his chicken shed. It is isolated enough to use some traditional “musical” instruments without disturbing the neighbourhood or attracting too much of the wrong kind of attention.
It is, of course, the same idea as the little quiet corner of the bedroom that we might have reserved for meditation practice, but it is a wonderful thing to have.