A few weeks ago I went on a tour of Parliament (which lest you should think it boring, is also the Palace of Westminster!). In order to do so you need to contact your MP.
I saw the House of Commons, the House of Lords, the monarch’s Robing Room, and much more! For example, Westminster Hall (which was built almost a thousand years ago) was the place where William Wallace was executed, Thomas More was condemned to death, where coronation banquets were held and where the exhumed Oliver Cromwell was declared guilty of treason.
Unfortunately you’re only allowed to take photos of Westminster Hall, so I can’t marvel you with the photos of pomp and gold but I can assure you that it’s worth the trip and the 75 minute guided tour (which focuses massively on how the English Civil War threw out the monarchy). The House of Commons is much, much smaller than you’d think and the eternally hanging microphones are extremely strange constantly sliding in and out of focus.
What I can say is that if the business of government moved out of the Houses of Parliament tomorrow, they could instantly become a museum. The throne in the House of Lords takes up a whole wall and is made of SOLID GOLD! You should definitely go.