When we think of historic buildings, we British tend to go long. Because we’ve got the benefit of many centuries worth of architecture, we reckon that Hampton Court Palace, The Globe Theatre and Stonehenge are historic. Unless it was visited by the original Queen Elizabeth, it just doesn’t seem very old.

Of course, we can grudgingly make exceptions if there’s an important connection.

The great stately homes, lived in by the wealthiest men of their time, still draw crowds, and so do the smaller homes that were inhabited by the prominent authors, politicians, musicians and explorers of past years.

I know, because I’ve been to plenty of them myself.

And I’ve invariably enjoyed them. The feel of history around you is intoxicating for everybody – children love it as well.

You have to tell them stories, of course, but once you’ve started off kids on tales that end with grisly murder, courageous victory or the shock that people really lived in an era with no computers, they’re normally hooked all the way to the gift shop.

As a nation, we spend a great deal on preserving this history. Quite right, too – if we lose interest in our heritage, then we’re pretty much sunk as a culture.

But there’s always a danger that by highlighting the perfectly preserved houses, we neglect the more grimy, earthy parts of our past. And those are often the most interesting bits.

Take Bushey Arches, for instance. Not so much the bridge that soars overhead, but what sits beneath those spans, in the middle of the roundabout. It’s a squat, brick-build building with slit windows, and it’s a monument to so much.

Because that there is a pillbox – one of the hastily built defence buildings that went up either in the years before the start of the Second World Warhad broken out.

The idea was that if German forces invaded, they could be repelled by British soldiers who were based inside these brick fortresses.

There are four holes in the front, two in the back.

There’s a door. And that’s pretty much it, other than very thick walls and a tough concrete roof.

These things were not built to be pretty, but to be robust.

They were built in a hurry, too, and they were designed with a specific strategic purpose – to defend London and slow down invaders.

All around the capital, pillboxes such as this were constructed to produce something called the London Stop Line Outer, a ring of varied fortifications that followed a line not so very different to the M25.

Tank traps, ditches, gun emplacements and pillboxes scattered along every route that it was feared German soldiers might use.

So if you want real history, there it is.

That little box underneath Bushey Arches was part of the last line of defence, a tangible sign of the fear that gripped Britain just 70 years ago.

There is another pillbox just behind Bushey station, and one in the Withey Beds near Moor Park, which has been converted into a bat roost.

Great idea – it stops the building being demolished, and helps animals into the bargain.

In Patchetts Green, there’s a pillbox designed to defend Elstree Aerodrome and no doubt there are more of these fortifications around – and I would love to know where.

But the point is that, too often over recent decades, we have cheerfully allowed buildings such as these to be demolished in order to make way for new developments.

Particularly in the 1970s, Britain went through a phase of replacing interesting and informative old buildings with hideous, badly designed new ones that have themselves now been rightly bulldozed.

And we do live in places crammed with history.

If you don’t believe me – go online and search for Locally Listed Buildings in your area, and revel in the details that’s there.

I guarantee – guarantee – you’ll mean to read one page, and end up reading lots more. Who knew, for instance, that there’s a tunnel at Aldenham Reservoir – or that the reservoir was built by Napoleonic prisoners?

But it’s the more recent buildings that are under threat.

While you’re online, check out Derelict London, an astoundingly evocative and beautiful guide to the dangers and sadness of allowing glorious buildings to fall apart around us. Harperbury Hospital anyone?

It saddens me hugely when we allow our recent heritage to fall apart.

I studied History with fascination, so I would say this, but if we don’t understand how we go to this point, we can’t make informed decision about the future. It’s also about the regret over wasted opportunities when useful buildings are simply left to nature.

If West Watford station is never to carry passengers again, surely something better could be done with that site.

It needs invention, creativity and determination, but instead it gets a padlock and a fading sign about security.

History is what inspires us. It reminds us of past successes and failures, and we ignore it at our peril.

It provides us with our best stories, our touchstone with the past– it’s only three or four generations since those pillboxes were being built by resolute, nervous people fearful of invasion.

In the intervening years, though, some 20,000 pillboxes have been demolished or allowed to fall apart. Across Britian there are now about 5,000 left, including those in Watford, Bushey and Patchetts Green, and we need to look after them.

Inside those bare walls, something special will always resonate.