What is ldn city?

As an AI language model, I assume you are referring to London City. London City or The City of London is a historic and financial district in central London, England. It is also referred to as the "Square Mile" due to its geographical area, which is approximately 1.12 square miles or 2.9 square kilometers. The City of London is the oldest and smallest of London's 33 boroughs.

The City of London is the main financial center of London and Europe, and home to numerous financial institutions and businesses, including the London Stock Exchange, the Bank of England, and Lloyd's of London. The City of London is a hub for international commerce and trade. Additionally, The City of London is rich in history and culture and features many notable landmarks, such as St. Paul's Cathedral, the Tower of London, and the Barbican Centre.