Add ovals to the tops of the four posts. Draw a horizontal line through the center of each oval. Sketch a slightly curved line connecting the two center ovals. Draw the center dome with a half-circle. Add a second curved line and a horizontal line underneath the center dome as shown.
Sketch a sideways V-shape on each side of the large dome. Add vertical lines underneath. Top each V-shape with a dome. Add arches with double curved lines and pointed tops. Use straight horizontal lines underneath some of the arches as shown. Detail the surface with vertical and horizontal straight lines and rectangles.