The Public Record Office was created in 1838 and had responsibility for government and court records. It was based in Chancery Lane, Central London, but opened another site in Kew in 1977. In 2003, it merged with the Historical Manuscripts Commission to form The National Archives (TNA). TNA's building sign was taken down recently to reveal the former Public Record Office stonework - an unexpected reminder of the past on a building that is dedicated to exploring the past.
TNA is currently hosting an excellent (and free) exhibition about Treason where you can view records relating to the Gunpowder Plot and other acts of treason from the past 700 years: https://www.nationalarchives.gov.uk/treason/
