Once a medieval fortress, Scotland's Edinburgh emerged in the eighteenth century, nicknamed â€œAthens of the North.â€ Today, the city preserves landmarks from centuries past, as well as the remains of geologic processes that occurred millions of years ago. But human and natural impacts on the area are visible from space.
The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite captured this image of Edinburgh on October 2, 2007. In this simulated true-color image, green indicates vegetation, deep blue indicates water, red-brown indicates bare ground, and grey-blue indicates buildings and paved surfaces.
The country's capital since 1437, Edinburgh is Scotland's second-largest city, after Glasgow. Although Edinburgh has expanded to incorporate neighboring towns and ports such as Leith, the city's historic center remains centered around Old Town and New Town. Old Town dates back to medieval times. Centuries ago, limited space for development encouraged the residents to build multi-storey buildings, some over ten stories high. Old Town retains the street pattern established long ago, with crooked, close-together thoroughfares. More spacious is the layout of New Town to the north. Designed along Neoclassical ideals, New Town presents an orderly grid. Together, Old Town and New Town were designated as a UNESCO World Heritage site in 1995.
Edinburgh Castle sits atop a feature known as Castle Rock. Castle Rock is a plug of basalt that seals the vent of a volcano that was active between 350 and 400 million years ago. During the Pleistocene Ice Age, eastward-moving glaciers eroded the volcanic plug, creating the natural landscape seen today. The area's earliest inhabitants considered Castle Rock a natural fortress, and archaeological excavations indicate that people lived at this site as early as 850 BC. East-southeast of Castle Rock is another dormant volcanic plug later sculpted by glaciers: Arthur's Seat.
Edinburgh's proximity to the sea gives the city a mild climate, with average daily lows that remain above freezing, and similarly mild summertime temperatures. It averages 685 millimeters (27 inches) of rain per yearâ€”a moderate amount of precipitation that provides lush vegetation.