This is a well known feature of a historical british house.
Let us know what building this is by tweeting @WhatBuilding to win a prize.*
*There is no prize
Hardwick Hall, in Derbyshire, is an architecturally significant Elizabethan country house in England, a leading example of the Elizabethan prodigy house. Built between 1590 and 1597 for the formidable Bess of Hardwick, it was designed by the architect Robert Smythson, an exponent of the Renaissance style of architecture.