For the 29th International Puzzle Party, held in San Francisco in August 2009, Kate designed a puzzle with a famous local landmark in its theme. The Lombard Loops puzzle consists of 12 curvy polybends pieces that wind and twist around 18 islands, much like the precipitous curves of San Francisco's Lombard Street, the "world's crookedest road." Each size has its own color, from a single quarter-arc to two, three, and four units joined. This limited-edition puzzle was adapted from the more extensive and permanent ChooChooLoops set.
The picture above shows a nice continuous path, and there are many different such solutions, even with a closed loop. However, it is not a complete solution for the Lombard challenge. The goal is for one continuous path to start in a corner circle at one end of the board and finish on the diagonally opposite corner. See diagram at right for start and end positions. The donut-shaped piece is a separate loop and can surround any island. Explore solutions for each of its positions.
