The name is the picture. Take a very large pipe, cut it in half along its length, and lay it open side up on the ground. What you get is a U: a rounded floor in the middle and a high curved wall rising on each side. A rider goes back and forth across the U, trading speed for height, and the tricks happen in the moment they shoot past the top edge.
One branch
同一個 U 形場地，兩種材質
兩個意思的形狀完全一樣，分家的地方只有一個：這個 U 是用水泥蓋的，還是用雪整出來的。
noun · B2
A large concrete structure shaped like a pipe cut in half along its length, with a rounded bottom and two high curved sides, which skateboarders ride up and down to do tricks.
U型滑板池