I was thinking more along the lines of a hash:

my %map = (
  name    => 'foo.map',
  author  => 'baz',
  width   => 250,
  height  => 300,
  tileset => 'forest',
  tiles   => [ 'dirt1.jpg',   # half dirt, half grass
               'mud1.jpg',    # half dirt, half mud
               'grass1.jpg',  # grass with a few shrubs
               'trees1.jpg',  # sparsely populated with trees and many
+ shrubs
               'trees2.jpg',  # moderatly populated with trees, less s
+hrubs
               'trees3.jpg',  # heavily populated with trees, sparse s
+hrubs
               'stream1.jpg', # stream running north/south (variation 
+1)
               'stream2.jpg', # stream running north/south (variation 
+2)
               'stream3.jpg', # stream running northeast/southwest
               'stream4.jpg', # stream starts in northeast but winds a
+way to the west
             ],
  layout  => [
               [ 1 6 1 0 2 2 3 ],
               [ 1 7 1 0 2 3 3 ],
               [ 1 8 1 0 2 3 4 ],
               [ 6 1 0 2 3 4 5 ],
               [ 7 1 0 2 3 4 5 ],
               [ 9 1 0 2 3 4 5 ],
               [ 1 0 2 3 4 5 5 ],
               [ 0 2 3 4 5 5 5 ],
             ],
  );
[download]