The urban lifestyle has a profound effect on mental health, contributing significantly to the challenges faced by people who reside in urban areas. Growing empirical evidence underscores the potential of nature to alleviate these mental health burdens. However, we still lack understanding of which specific natural elements provide these benefits. Using eye‐tracking technology, we experimentally explored the relationships between intentional visual attention to natural (green) and human‐made (grey) elements in urban areas and their association with well‐being measures. Participants took a 45‐min outdoor walk that simulates a walk to and from work, in which we examined pre‐ and post‐measures of cognition, affect, anxiety and perceived restorativeness. Participants were prompted to direct their attention to green, grey or a mixture of both elements. By analysing participants' eye movements and patterns, we determined adherence to experimental conditions and related visual attention to natural elements. The experimental groups instructed to direct their visual attention to green, grey or a mix of both infrastructures exhibited differences in negative and positive affect, anxiety and perceived restorativeness, but not in cognition after a walk in an urban environment. The percentage of time spent viewing natural elements showed that people who focused more on green features reported a decrease in anxiety and higher perceived restorativeness. In contrast, those who spent more time viewing grey elements reported increased anxiety and lowered perceived restorativeness. The percentage of time viewing natural elements was not linked to affect or cognition. Viewing trees showed the strongest association with well‐being measures compared to other natural elements. Together, our results indicate that a simple behaviour change (directing visual attention to elements of nature instead of grey elements) can produce mental health benefits in the form of reducing anxiety and perceived restoration for people in urban areas. Thus, efforts to integrate nature, especially trees, in urban areas and promote city dwellers to visually interact with it during their daily routine can improve mental issues associated with urban lifestyle. Read the free Plain Language Summary for this article on the Journal blog.