this is the place where you worked. this is the place which you visited. 看看两句,为什么先行词都是place,而填的关联词不一样呢?就是因为第一句话中先行词做状语,等于you worked in the place,所以用where这个关系副词做时间状语。而第二句话是you visited the place,这个the place 做visited的宾语,所以填which做宾语。所以区分还是要看在从句中做什么成分。
追问那从句中的不是visit呢