of land and sea Baseline roads cover 52,587 miles (84,631 km), in addition to 17,567 miles (28,272 km) of rivers and canals Map reveals how much it would have cost to travel on roads and seas ...

Estuaries are dynamic ecosystems that have some of the highest biotic diversity and levels of production in the world ... river discharge regions where the valley is presently not drowned by the sea.