By Mark Simpson BBC NI political correspondent

If the Northern Ireland Assembly collapses soon, its memory will survive in the form of mugs, pens and humbugs.

For political enthusiasts, the Stormont souvenir shop is the equivalent of Disney World.

On offer are pens, pencils, books, coasters, chocolate bars - and even fudge.

As the assembly hits another sticky patch, there are plenty of items in the gift-shop which could be valuable mementoes one day.

And it seems there is no shortage of business.

Assembly fudge is among gift items on sale

On average, around 40,000 people a year come to see Stormont.

The latest figures show that visitors from 118 different countries have climbed the steps to Parliament Buildings in the past four years.

Their countries of origin range from Iran to Israel, from China to Colombia.

When it comes to historic properties in Northern Ireland, Stormont's Parliament Buildings is in the top five tourist attractions - with more visitors than Belfast City Hall, and the picturesque Castle Ward in County Down.

One of the questions most frequently asked by tourists is - why is it called Parliament Buildings when there is in fact only one building?

The answer is that originally there was supposed to be law courts on one side of the main building, and the headquarters for the civil service on the other.

But in the end, they ran out of money!

The building, which sits on a hill on the outskirts of east Belfast, dates back to 1932.

'Rocking Rod'

Back then, it is difficult to imagine that politicians ever envisaged rock concerts on the front lawn.

The sight of Rod Stewart on stage singing "Do ya think I'm sexy" is hardly what they had in mind ....

But in July, rocking Rod will follow in the footsteps of Elton John and the Eagles by performing in the annual Stormont concert.

You have to pay to go - but the Stormont tour is free.

US students on Stormont's famous steps

Like most things in Northern Ireland politics, there is, however, a pre-condition.

Any group wanting to be shown around must have the permission of an assembly member.

The reason is simple. It may be a popular tourist attraction, but Stormont's primary function is as a place of work.

For members of the assembly, Stormont is their "office", and most workers in any business would complain if coach-loads of tourists were trampling over their desks all day.

Tours are therefore limited, but barely a day passes without two or three buses pulling up outside Parliament Buildings.

And it is not just the pro-Agreement parties which are inviting people to come up to see around.

DUP members and other anti-Agreement unionists are more than happy to invite people to see devolution in action.

They may disagree on most other things, but all the parties at Stormont say "yes" to visitor tours.