BBC Four HD Wednesday

Horticulturist Monty Don visits the private oasis of Brazilian artist Burle Marx and witnesses the floating gardens of the Amazon while touring the lush vistas of South America

The host focuses on the role played by water in the creation of weather, discovering how rain could crush a car, trying to build his own cloud and starting an avalanche

The final instalment reveals how, in the late 1970s, corruption within the City of London's CID had grown out of control

Actor Alison O'Donnell looks back at the long-running crime drama, recalling how she got the part of 'Tosh' and reflecting on her experiences of working on the show

Perez and the team investigate when body parts belonging to a young man are discovered on the island, Drama, starring Douglas Henshall

Travelling across the Shetland Isles, Ben Fogle meets people whose lives are rooted to these islands' history and visits a tiny church with big ideas

Horticulturist Monty Don visits the private oasis of Brazilian artist Burle Marx and witnesses the floating gardens of the Amazon while touring the lush vistas of South America

The host focuses on the role played by water in the creation of weather, discovering how rain could crush a car, trying to build his own cloud and starting an avalanche

The final instalment reveals how, in the late 1970s, corruption within the City of London's CID had grown out of control