Like his other pieces completed later on in life, A Gate shows elements of Surrealism and Cubism more than it does any recognisable type of Realism. This painting was one of the works completed in the last years of his life.
The gate is suggested using abstract forms. In a way, while this is a cityscape, it brings natural stone to mind. It has long oblong structures which are sometimes found in the natural world. In another way, the gate may be reminiscent of Stonehenge or other henges which are found throughout Europe.
Henges or circles of stone are considered to be prehistoric. The fact that Klee can evoke this sense of something prehistoric in what is a painting focused on an aspect of modern life, speaks to his skill as an Abstract artist. Some people think of Stonehenge and other henges as gates leading to supernatural aspects of the world.
Klee has built a structure that is formidable. The pillars are immense as they reach to the sky. Their base is also solid, so it would not be easy to break through without permission. While is used to introduce light around each block. This makes the gate inviting even as it shows its strength.
The original title of this painting was Ein Tor. The original painting is currently in the collection of the Beyeler Foundation. The Foundation owns several of Klee's later works and primarily focuses on his Abstract paintings. The pieces have been seen in exhibitions which they have organised near Basel.
The colour chosen by the artist is significant. In most of his work, he uses more than one shade to produce the effect that he desires. Here, he has chosen to focus his efforts using just one shade.
Everything is grey. This may be for a wide variety of reasons. Perhaps he wants to invoke a sense of a grey, modern city. One that is devoid of the colour that would normally be found in a garden or a park. Perhaps he wants the almost silvery finish to speak of metal. This is another feature of modern cities.