It was in the basement of the Houses of Parliament that Guy Fawkes hid the gunpowder he famously hoped would spark a revolution.
Now, four centuries on, the Palace of Westminster’s cellars are again causing concern. Here, in the depths of the building, the scale of repair work urgently required can clearly be seen.
Ancient pipe work, outdated electrics and faulty drains can be found. Roofs leak and the threat of fires caused by eroding infrastructure is serious.
One MP told The Scotsman the scale of the work could not be accurately quantified as no one knew exactly how much needed to be replaced.
A timetable for works has not been agreed. The Public Accounts Committee said in March that moving everyone out of the building while work was carried out was the “most economic” and “the most effective choice”.
But some MPs and peers want to remain in the building.
Conservative MP Shailes Vara claimed leaving Westminster for a temporary home would send the wrong message during Brexit negotiations.
“At a time when we are seeking new friends and new trade deals, we should be making the most of this iconic building,” he said.
“This is clearly the wrong time to be selling UK plc from a temporary construction in the courtyard of a government department.”
An independent report found restoration of the Houses of Parliament without moving members out would cost £5.7bn and take 32 years.
If MP and peers were moved out for six years, the cost would drop to £3.5bn.
Neil Gray, MP for Airdrie and Shotts since 2015, said Westminster was “in a very bad condition”.
“The problem is we don’t know just how bad it is - the initial cost assessments have to be taken with a pinch of salt,” he said.
“We’ve looked at the basement, but won’t know the full scale of the problem until work starts. The official figure in the report was £4bn - but I think you can double it.”
The SNP parliamentarian was a critical member of the joint select committee established to consider the palace’s renewal.
He tabled an amendment arguing for “full consideration” to building an alternative and more practical new parliament, but was voted down 11-1.
He added: “Sadly, I think the opportunity in terms of planning for parliament to move around the country - which would have been a fantastic opportunity - that ship has sailed.
“The opportunity of a new build parliament has also been lost. We will now crow bar a 21st century parliament into a neo-gothic 19th century building. The question has to be asked if this is best use of taxpayer money?”
The existing Palace of Westminster is the work of Charles Barry and was completed in 1847. Its rebuilding followed a devastating fire in 1834 that destroyed most of the original medieval warren of buildings, with the notable exception of the 11th century Westminster Hall which still stands.
The disaster had been predicted - a 1789 report warned against the possibility of fire in the palace. Signatories included the leading Scottish architect Robert Adam.
MPs are due to next debate the UK’s trickiest renovation project in January.