The British Geological Survey at Keyworth opened its doors so the public could view some of its most precious artifacts this weekend. JENNIFER SCOTT took the one-off tour

ADINOSAUR'S footprint. Some original Charles Darwin findings. And the cast of a dodo's head.

These were just some of the intriguing artifacts on display at the British Geological Survey's Records Centre at Keyworth this weekend.

Guided tours offered experts and members of the public the chance to view rarely-seen items from the BGS's enormous collections that span almost two centuries of findings.

Visitors could see the first ever scientific map of any country ever produced – William Smith's famous geological map of England and Wales.

They could view a raunchy statue of Hercules from the 1851 Great Exhibition which made the survey director's wife blush so much she demanded certain body parts be removed (at a cost of seven guineas) and replaced with a fig-leaf. Hercules' former glory was restored in the 1970s.

They could even don glasses to take a 3D tour of the surface of Mars via a cinema-sized screen, which enables you to zoom in on land formations like an enormous volcano and possible liquid deposits.

The BGS's archives are gloriously wide-ranging.

In all, there are 500 people who work on the site and around 250,000 specimens in the collections yet – as one of the archivists notes – "Many people don't actually realise we're based here."

It's not just the collections themselves that are startling but also the stories behind them.

One of the BGS's first overseas surveys – an 1846 excursion to map the coalfields of India – saw the unfortunate geologist fall from an elephant down a precipice. He eventually died of jungle fever. Another English explorer disappeared into the rainforests, never to be seen again.

The archives contain the skin of a massive anaconda which was shot by a geologist in Bolivia in the 1970s in self-defence.

The BGS was originally founded in London in the 1830s – the start of a golden era for science and exploration.

"The idea back then was to educate the public in the value of geology because, at that time, it was a new science," explains Mike Howe from the materials collections. "Geologists at the time were amazed at the efforts being put into tunneling into rocks in Wales that could not contain coal. The BGS came into being to improve the efficiency of looking for coal and limestone."

Accordingly, the BGS's vast material collections store today contains 11 metre high shelves, stocked with core materials – rock samples collected from drilling into the ground – from all over the world. They include the first ever material collected from Antarctica and material collected by Charles Darwin.

During the 1970s, the BGS decided to move to a university campus. A deal was almost struck with Nottingham University but the site was too small. In the end, the BGS moved into a nearby teacher training college at Keyworth where they've been based ever since.

The BGS has worked with the likes of Andrew Marr – on his recent Britain From Above series – and hopes to assist Sir David Attenborough next year.

Yet they also have a hugely relevant purpose for we mere non-media mortals – to help modern society understand better what is going on underneath their feet.

This is best demonstrated in the inquiries office which receives 50 queries every day.

Often these come from developers seeking to build roads, supermarkets, pipelines or windfarms. Many also come from homeowners who are perhaps seeking to make a purchase and want to know how sound their investment would be. In one case, the BGS advised a man that an apparently good-value house on a cliff in the Isle of Wight may not be a sound investment.

A few years later, the house had fallen into the sea, leaving the potential buyer quite relieved he'd checked.

People who wish to renovate buildings also seek advice from the BGS as to how they can best match the original stonework. The BGS advised on high-profile projects like St Pancras Station, as well as more local schemes such as a church in Basford.

"People probably don't realise we have all this information to hand," says Rachel MacKenzie from the inquiries office.

The BGS also provides a free web-based service aimed at schools and amateurs. If they find a rock in their garden and want to find out more about it, they can log on for advice. Downloadable fact sheets on subjects like volcanos are also available.

Although Saturday's Open Day was a one-off event, the BGS is normally available to visit – although not all of the artifacts mentioned above will be on display. During National Science and Engineering Week in March, schools can register to come down to the centre and practise panning for gold or jumping up and down to create an earthquake.

For more information, or to book a tour, call 0115 936 3143 or email enquiries@bgs.ac.uk