The outline of the castle on the hill was clearly defined against the evening sky.
It is a mixture of commentary, topical essays (on angels and space, the elements, light, the sky, planets, spheres, heaven and earth) and source book.
In this image, a parapet separates an outdoor porch or balcony from a background landscape of sky, trees, hills, and water.
Days are rainy only when skies are cloudy, but rainy days do not make cloudy skies obligatory.