What is the most money in free parking in Monopoly?

According to the official rules of the game of Monopoly, no reward of any kind is offered for landing on Free Parking. Many people play by "House Rules," and they often vary by community.

The game is started by putting $500 in the middle of the board. Each time you need to pay the bank for a Chance or Community Chest card, that payment, too, is put into the middle. When someone lands on Free Parking, he wins what is in the middle, and a new $500 bill is put in the center.

A similar local game variation is: When you land on Go, you receive double the amount ($400 instead of $200) from the bank.