The busiest streets of Edinburgh are full of shops. Prince Street divides Edinburgh into a new and old city, a new city to the north and an old city to the south. There is a long hill between the new and old cities, and the natural barriers are distinct. Princes Street is known as the world's best road. Just a full length, many gorgeous and modern shops gather on this road. On the south side is a verdant green area, and at the end of the east end is the Prince Street Garden. The prince street garden under the castle is picturesque, with a memorial tower of the famous Scottish writer Scott. On another green area of the garden stands the world-famous Scottish clock, whose main structure is underground. This clock was built in 1803. The minute hand is 2.4 meters long, the hour hand is 1.5 meters, the clock face is 3.5 meters in diameter, and the flower clock pattern is composed of 24,000 flowers. Every time a minute, a rhododendron jumps out. It is said to be the largest and most unique flower clock in the world. During the literary festival, the Princes Street Garden is full of flowers, and the artists in traditional kilts play the bagpipes from time to time in Princes Street Park. The Scottish Art Gallery is also located outside the garden. To the north of the garden is the bustling commercial street of Edinburgh. In the north of the new city, there is the Royal Botanical Garden, which covers an area of 30 hectares. There are many varieties of rhododendrons in the park, and the number is the highest.