A Portuguese fort takes a star turn

Perched on a strategic hillside, high above the hot, dry plains of eastern Portugal, the Nossa Senhora da Graça Fort has been called a masterpiece of 18th-century military architecture. The thick walls that surround the fortress are shaped in a star pattern, with pentagonal bastions jutting out from the curtain wall at the corners. We're looking at one of those bastions coming to a point in the lower center of our image.
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