Arrábida Natural Park ?
Natural Reserve of Sado's Estuary ?
"26 Roaz (Tursiops truncatus) dolphins inhabit the Sado estuary at present.
This is the only population resident in an estuary in Portugal, and one of only three known dolphin communities in Europe."
This is the only place, that we know of, where we can see a comunity of dolphins living in a beautiful river estuary surrounded by heavy polution industries!
And the Dolphins still resist !!!