1. Place a rectangular house. Turn the house into a flat platform. Reduce the roof height to a minimum (remove the roof), reduce the wall height to a minimum, raise the bottom level of the platform to the height of the bridge. Make the length and height of the platform the same as the bridge

2. Place a short wall two or three bricks long.

3. Right-click on the wall and you will see two line points. Drag one point and make the length of the wall the same as the length of the flat platform.

4. Take the tool - path. Draw a path under the wall along the bridge. The walls will turn into arches.

5. Change the wall height to the minimum.

6. Change the arch height to the height of the bridge railing.

7. Right-click on the arch. The arch editing mode will appear. Move the cursor to the area between the dotted lines, the scissors mode will appear. Cut one arch along the column.

9. You have two arched walls. Select the first wall, enter wall edit mode, select a line point and stretch the wall along the rectangular column.

10. Stretch the length of the second arched wall. Move the arched wall, select the cross arrows in the arched wall edit mode and move the second arched wall so that the arched columns alternate by half a column pitch.

11. Make different variations.

12. Play with the arch design.