Longitude lines run vertically (north–south) from pole to pole and measure how far a place is east or west of the Prime Meridian (0° longitude), which passes through Greenwich, near London. Longitude is closely linked with time zones. As the Earth rotates, different longitudes experience sunrise and sunset at different times. Using both latitude and longitude together, we can find the exact location of any city, island or landmark on the globe—for example, New Delhi is roughly at 28.6°N, 77.2°E.