A sandlot is a piece of empty land in a town or city where children go to play games, especially ball games. It is mainly an American word. The “lot” is a plot of land — the same idea as a vacant lot or a parking lot — so a sandlot is not “a lot of sand,” and the ground may only be dusty earth. In American stories, sandlot baseball means kids making a game themselves, with no real field and often no grown-up in charge. The word feels informal and a little old-fashioned: people still know it, but you are more likely to read it in a book or hear it in a film than to see it on a street sign.

（城市裡給小孩打球的）空地