Collect a free admission ticket from the booth by the gate of the Royal Observatory and enter the courtyard. The Observatory is the home of the Prime Meridian. The Line is clearly marked by a strip on the ground leading up to a stainless steel sculpture. The glass shard at the tip of the sculpture is the white marker you used to walk up the Meridian Line in the park. People from around the world come to have their picture taken standing astride the Prime Meridian.