Description from the publisher:

Peloponnes Heroes and Colonies will add Heroes with individual powers to the players and Colonies, which replaces the playerboards from the original game. All Colonies have different advantages and disadvantages.
A new "disaster" added with the Persians, who strikes twice in the game.
Gain strength while adding buildings and land to your civilisation to defend the Persians and other players.

Peloponnes Heroes and Colonies is a big new expansion for Peloponnes that comes in the same box size as the "Peloponnes Box"....