SQL query to count most "popular" value?

These are my tables:

Table: People

id---name
1----John
2----Mike
3----George

Table: Visits

id---name---visitor
1----Paris--1
2----Paris--1
3----Paris--1
4----London-1
5----London-1
6----Tokyo--1

Now from those tables we can read that a person named John (id 1) has visited Paris three times, London twice and Tokyo once. Now my question is how could I translate this into SQL and select the name of the most popular place John has visited (result being Paris)?