Tainan had been Taiwan’s capital for almost three hundred years when, in 1625 the Dutch arrived in the city. After the 1653 uprising against them, they built Fort Provintia, and made it the hub of their administrative and commercial activities.
The entrance to the fort was now nothing more than a sealed off archway, and at the back of the complex a corner had been excavated to reveal part of one of the original bastions.
Built on the foundations of the old fort was Wenchang Pavilion that had been constructed in 1886 to encourage education. Next to it, where the south-western bastion once stood, was Haishen Temple built in appreciation for the protection offered by the sea god, Haishen.
For over three centuries Chihkan Tower had been a castle when Taiwan was under Dutch rule, a Chinese style pagoda in the Qing dynasty, an army hospital during the Japanese colonial period, and today a museum.
From here to there 
This is an interesting snippet of Taiwan’s history. I guess the fort was sealed off as there was no need for it. But from your photo it looks like it has held up well over the years.
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