Edinburgh is the second largest city in Scotland. It has a population of around 477,660 people within an area of 259 square kilometers, resulting in a population density of 1,844 people per square kilometer. The historic center of Edinburgh is divided into the Old Town and New Town by Princes Street Gardens. Both the Old Town and New Town were declared a UNESCO World Heritage Site in 1995 for retaining their historic character. The Old Town maintains its original medieval layout and landmarks, while the New Town was designed in the 18th century to accommodate population growth from the overcrowded Old Town. Edinburgh experiences a mild maritime climate with average summer temperatures of 13 degrees Celsius and winter seasons that are generally quiet.