[Retros] destination squares

[Richard Stanley]

One of John Nunn's 2012 Christmas puzzles (#5 at 
http://www.chessbase.com/puzzle/christmas2012/chr12-05.htm) is to find a 
game of chess (ending in mate) with a total of three destination squares.
Here are two related questions. It is possible that the solutions are 
unique. Perhaps Francois can confirm this.

1. Find the longest game of chess (not necessarily ending in mate) with
    only two destination squares.

2. Find an infinite game of chess with three destination squares.

Richard