Banqueting house

It may be raised for additional air or a vista, with a simple kitchen below, as at Hampton Court Palace and Wrest Park, and it may be richly decorated, but it normally contains no bedrooms, and typically a single grand room apart from any service spaces.

There are usually plenty of windows, as appreciating the view was a large part of their purpose.

In the English of the period, "banquet" had two distinct meanings: firstly a grand formal celebratory meal (the usual modern sense), but also a course or light meal taken in a special place away from the main dining place, the relevant sense here (Whitehall apart).

Otherwise it might be used on fine days for taking tea, or any kind of drink, snack or meal.

Similar buildings, under various names such as "pavilion", appear in the architecture of European and many Asian countries.