欢乐谷的英文名称是 "Joyland"。这个名字的来源可能是因为欢乐谷是一个游乐场，而游乐场通常都会让人感到快乐，所以起名为 "Joyland"。

一些英文例句和中文翻译如下：

"I spent the day at Joyland with my kids and we had a great time." (我和我的孩子们在欢乐谷度过了一天，我们玩得很开心。)

"Joyland has the best roller coasters in the city." (欢乐谷有城市里最好的过山车。)

"We are going to Joyland on Saturday, do you want to come with us?" (我们周六要去欢乐谷，你想和我们一起去吗？)