The British city you are referring to is Edinburgh, Scotland. It is often referred to as "Auld Reekie" due to its smoky atmosphere from the burning of coal, and "Athens of the North" due to its many neoclassical buildings and monuments.
Edinburgh is the British city that has the nicknames Auld Reekie and Athens of the North. Auld Reekie is a Scots term for "old smoky" and comes from the city's historic chimneys and smoke-laden air. The nickname Athens of the North refers to Edinburgh's reputation as a center of intellectual and cultural activity during the Enlightenment.
Edinburgh, the capital of Scotland, is renowned for its historic and cultural significance. The nickname "Auld Reekie" refers to its past smoky atmosphere, while "Athens of the North" highlights its intellectual and cultural heritage.