In the early 17th century, European seafarers came to Asia to trade and develop colonial outposts. In 1624, the Dutch occupied today's Anping and took ten years to build a fort named "Fort Zeelandia." After 1662, because Koxinga and his son lived here, it was named "King Castle," "Anping Castle" as well as "Taiwan Castle." The Japanese rebuilt it and named it "Anping Old Fort." Today, the only Dutch remains are the ruins of a semicircular bulwark and a section of the outer fort's brick wall; the root of an old banyan tree on the wall remains a witness to the fort's long history. Its commanding views of the ocean make it a popular place to watch the sunset. Nevertheless, the fort itself is not that impressive, and neither is the view from the tower during the day. Also, there is not much space in the tower, so it is questionable that many people will be able to enjoy the sunset. Hence, you could skip it for Anping Tree House instead.

Fort Zeelandia (Chinese: 熱蘭遮城; pinyin: Rèlánzhē Chéng; Pe̍h-ōe-jī: Ji̍at-lân-jia Siâⁿ; Tâi-lô: Jia̍t-lân-jia-siânn) was a fortress built over ten years from 1624 to 1634 by the Dutch East India Company (VOC), in the town of Anping (now Anping District of Tainan) on Formosa, the former name of central island of Taiwan, during their 38-year rule over the western part of the island. The site had been renamed several times as Fort Orange (奧倫治城), Fort Anping (安平城) and Taiwan City (臺灣城) . The current name of the site in Chinese means Anping Old Fort (Chinese: 安平古堡; Pe̍h-ōe-jī: An-pêng Kó͘-pó).

During the seventeenth century, when Europeans from many countries sailed to Asia to develop trade, Formosa became one of East Asia's most important transit sites, and Fort Zeelandia an international business center. As trade at the time depended on "military force to control the markets", the value of Formosa to the Dutch was mainly in its strategic position. "From Formosa the Spanish commerce between Manila and China, and the Portuguese commerce between Macau and Japan could by constant attacks be made so precarious that much of it would be thrown into the hands of the Dutch, while the latter's dealings with China and Japan would be subject to no interruptions."

On behalf of the VOC, ships departing from Formosa could head north to Japan, west to Fujian, or south to Vietnam, Thailand, Indonesia, Cambodia, India, Iran or Europe.