after making you don't know how many visits

还可以表达为：

after making no one knows how many visits

after making God knows how many visits

"走到了不知什么地方"可以说：

went to God knows what place

came to no one knows what place

went to you don't know what place

what为疑问词，属于中位限定词，不可再用中位限定词 a 。（只有感叹词what才可以后接 a )

place为介词to的宾语，逻辑意思为没人知道这是什么地方，what修饰place。所以不能用where去修饰place。

这是比较口语化的表达。翻译考试只要语境、语体合适，为什么不可以用呢？