place of interest和sights两者都有风景名胜的意思。sights侧重于自然景观，places of interest 侧重于人文景观。
sight复数是sights；place of interest的复数是places of interest，interest根据意思不同，可以是可数名词，也可以是不可数名词，这里的interest是不可数名词。一般来说,如果不用复数形式时,我们可以说 a place of interest。
I went to the Summer Palace, climbed the Great Wall and went to many places of interest.我去了颐和园，登了长城，还去了许多有趣的地方。
There are many places of interest in Beijing. 北京有很多名胜古迹.
世界上著名、很有名的景点都有历史背景，包括美丽的风景，世界上著名的都用place of interest。
Eg：There are hundreds of places of interest along the Beijing-Hangzhou Grand Canal. 京杭大运河沿河一带有数百个名胜。
而sights 侧重指旅游观光的风光，包括城市景色或自然风光景色。也指人造景物或奇特的景色。
Eg：There are models of more than a hundred sights from all over the world in the park. 公园里有来自世界各地的一百多个名胜的模型。
Sights [复数] 名胜;风景
柯林斯字典解释 The sights are the places that are interesting to see and that are often visited by tourists
牛津字典解释 the interesting places, especially in a town or city, that are often visited by tourists
We're going to Paris for the weekend to see the sights我们打算去巴黎过周末，参观那里的名胜。
We'd toured the sights of Paris. 我们游览了巴黎的风景名胜。
I am going to show you the sights of our wonderful city. 我会带你浏览我们这座美丽城市的风景名胜。
综上所述，如果具体到著名景点就用place of interest, 其他情况我认为区别不大。欢迎交流！
