Summer Opening
While the Houses are in recess, the Palace of Westminster is generally closed - apart from the long Summer recess, during which tours are run through the building, led by Parliamentary employees. Popularity of these tours means you're best advised to book in advance - a stall ere

While the Houses are in recess, the Palace of Westminster is generally closed - apart from the long Summer recess, during which tours are run through the building, led by Parliamentary employees. Popularity of these tours means you're best advised to book in advance - a stall ere
Check the official site before travelling; hours and prices can change.
More museums

Sir John Soane's Museum
Free, tiny, deranged — Soane's own house preserved exactly as he left it in 1837.

The Wallace Collection
Free national museum in a Manchester Square townhouse — armour, Boucher, the Laughing Cavalier.

The British Museum
Free, vast, civilisationally heavy — go for one room, not all of them.
Source: wikivoyage