Nucleate boiling within an angular geometry, a basic geometry found in many structured boiling heat transfer surfaces, is investigated. Pool boiling tests are conducted using water at atmospheric pressure and a horizontal heated wall with an inclined wall attachment making a line contact to form an angular geometry. It is found that nucleate boiling from the horizontal heated wall is greatly enhanced by a favorable thermal environment within the angular geometry. The effects of the angle between the two walls, and roughness and length of the wall attachment are studied. The results reveal the importance of the angular geometry to the enhanced nucleate boiling heat transfer of structured surfaces, and provide information to the development of more effective surfaces.