It is the namesake of a time system that is equivalent to Coordinated Universal Time.
In 1999, a powerful north-facing green laser was added to this building. In 1894 it was nearly bombed by French anarchist Martial Bourdin, who inspired the character of Stevie in Conrad's The Secret Agent. This building was often called the Flamsteed House, and was built by (*) Christopher Wren in 1685. It is the namesake of a time system that is equivalent to Coordinated Universal Time. For 10 points, name this historical residence of the Astronomer Royal, a building whose location is the basis for the Prime Meridian.
In 1999, a powerful north-facing green laser was added to this building.
{Greenwich} Observatory [or Royal Observatory, {Greenwich}]