(CNN)Here's some background information about Great Britain's Houses of Parliament, located on the Thames River in London.
The meeting place of Great Britain's bicameral legislature - composed of the House of Commons and the House of Lords - is also known as Westminster Palace.
Security technology, such as CCTV cameras and alarms, are used throughout the estate.
In addition to unarmed security officers, armed police officers are also on the premises.
11th century - The original palace is built.
1604 -1605 - A group of English Catholics, including Guy Fawkes, plots to blow up Parliament to protest their treatment by the Protestants. However, the plot is uncovered and the conspirators hanged. November 5 is still celebrated in England as "Guy Fawkes Day", when people celebrate with bonfires and fireworks and burn effigies of Fawkes.
October 16, 1834 - A fire destroys most of the building.
1840 - Construction begins on the current Houses of Parliament.
1852 - House of Commons is first used.
1870 - Construction completed.
May 11, 1941 - House of Commons chamber is destroyed in bombings during WWII. It is rebuilt by architect Sir Giles Gilbert Scott.
1950 - The reconstruction of House of Commons is complete.
1987 - The United Nations Educational, Scientific and Cultural Organization (UNESCO) designates the building as a World Heritage site.
2000 - Portcullis House, a new Parliamentary building, is completed.
February 2001 - Portcullis House officially opens.
June 18, 2015 - An independent committee issues a report outlining the need for extensive repairs throughout the historic complex. Issues that need attention include wiring problems, loose asbestos and rats. The principal architect at the Houses of Parliament tells the BBC, "Some of the facades are actually sinking and we're going to have to investigate that very soon."