The journey has always been a crucial theme in cinema, whether of the emotional or psychological variety, where a character embarks on an arc of self discovery; or a geographical journey that takes them to a new life in a new place. The latter, of course, is frequently a metaphor for the former. In America the journey is a particularly potent dramatic theme. Discovered by explorers, populated by pioneers and later by immigrants from around the world, the nation and its psyche is built upon its ancestors’ journeys to a promised land.

Travel – the epic adventure on the open road – is often as attractive and evocative as the reason for that travel. Hence in cinema, for road movies like Easy Rider (1969) and Thelma & Louise (1991) the journey itself, rather than its end, is the goal. The idea of travel for the love of the road is something that came rather late in cinema’s evolution, perhaps a reflection of the literary mores of the Beat writers of the 1950s. The unanchored free spirit, the drifter, the doomed rebel: these are the characters who populate films like Two Lane Blacktop (1971), Vanishing Point (1971), My Own Private Idaho (1991) and David Lynch’s voyage of self-destruction Wild At Heart (1990).

But Hollywood is rather conventional at heart, so most cinematic journeys have to be justified by a goal that can be achieved by the close of the picture, giving the audience a satisfying sense of closure and the protagonists a purpose. Whether the initial aim of the journey is the one which turns out to be the real discovery is another thing entirely. Take The African Queen (1951), John Huston’s much-loved WW1 adventure which pitches together the mismatched couple of Humphrey Bogart as a grizzled, gin-swilling riverboat captain and Katharine Hepburn as a prim and proper missionary. The aim of their perilous journey down river is to try and sink a German battle ship but the real point of their adventure becomes clear when the pair fall in love.

Another example is David Lynch’s The Straight Story (1999), the tale of an elderly man who decides he must visit his ailing, estranged brother so that the pair can make amends before it’s too late. Although he no longer has a driving license, the fiercely independent Alvin Straight refuses to take a bus. Instead he customises his little lawnmower tractor and drives himself, all the way from Laurens, Iowa to Mt Zion, Wisconsin. Although he achieves his goal and is reunited with his brother, the point of the film is to show the lives he touches along the way.

However exploration, discovery or the chase to claim a prize have always been key to the high concept adventure movie. A quest, such as the one that drives Jason And the Argonauts (1963) with it’s terrific stop-motion animated special effects, or scientific curiosity, is enough to drive man to the outer reaches of the galaxy or to the centre of the earth. One of the earliest films ever made, George Melies’ 14 minute sci fi Le Voyage dans la Lune, demonstrates cinema’s fascination with exploration and with breaking the boundaries of our known world. Outer space is the domain of the new adventurers: like the conquistadors of the 16th century, the space explorers on a mission to Jupitor in 2001: A Space Odyssey (1968) are looking for new worlds. The astronauts and scientists in Danny Boyle’s Sunshine (2007) meanwhile are hoping to save their old one.

The lure of the unknown is not restricted to distant, unexplored galaxies – filmmakers have found plenty of inspiration right here on earth – or in earth in the case of Journey To The Center Of The Earth (1959). But the most poignant of journeys are those that lead the protagonist home, to be reunited with loved ones. It’s a popular theme in children’s films: examples include the little clown fish’s search for home in Finding Nemo for example; both the Toy Story films involve the quest to bring a lost toy back to the bedroom; PeeWee Herman’s Big Adventure follows PeeWee’s search to bring his stolen bicycle home. Which goes to show that, as we’re told in The Wizard Of Oz, one of the most colourful epic journeys of them all, there’s no place like home.