Every year, five million people visit London's Natural History Museum to see its incredible collection, from extraordinary dinosaurs to giant whales, and rare fossils to space rocks said to be as old as the solar system itself. But only a fraction of the staggering 80 million items in the collection are on display. Here cameras capture some of these incredible specimens, revealing the unique and rare pieces too valuable to exhibit.

The museum's dinosaur experts Susie Maidment and Paul Barrett follow up an exciting tip-off about some possible dino footprints in Wales. Meanwhile, the world's most famous dinosaur - Dippy the Diplodocus - is on a road trip around the country and needs an up-close inspection to make sure it's safe.

World-leading dinosaur expert Susie Maidment is in the museum basement trying to piece together the skeleton of the first Tyrannosaurus rex ever discovered. It’s a priceless specimen but somehow the bones have got muddled up with another dinosaur and it’s up to Susie to work out if any of the bits are missing. The experts inspect Guy the gorilla, who was a London Zoo favourite for decades and now sits fully preserved in his own glass case, and the museum launches an ambitious project to capture a sample of every living bug in the UK today.

Leading experts examine a rock in a crate of finds from an archaeological dig in Africa, which could contain a very rare 200-million-year-old dinosaur skull. The museum staff prepares for the Wildlife Photographer of the Year awards. Other artefacts from the museum featured in this episode include meteorite fragments that are older than the solar system and the oldest complete beetle specimens ever found in the UK.