Leviathan, by Scott Westerfeld, is a young adult steampunk novel set in an alternate-history Europe. The Great War is coming, but instead of the Allies vs Central Powers, it is the Clankers vs Darwinists. The Clankers have developed great steam powered machines, and the Darwinists have bred giant beasts as their weapons.
The map illustration is intentionally reminiscent of the "allegorical maps" of the period.
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