Puerto Rico National Historical Museum Site Castle, also known as the Morro Fortress (castle), was built in 1539, when pirates rampaged, the Spanish merchant fleet used it as a base, the fortress has experienced many wars, has experienced several restorations, and was selected for the World Heritage List in 1983. This is one of the must-visit attractions, belonging to the Spanish-style fortress of San Juan, built by the sea, the plot has a history of nearly 500 years or so, mainly used to resist the sea and ground attack, this is also the largest defense facility built by the Spaniards here. The castle successfully resisted the invasion of the English and Dutch, and the scenery was beautiful, overlooking the entire Old San Juan city and the coastline from high, and it was refreshing to see the blue sea level of the sky and earth, and it seemed to hear the rumbling of guns again, and the faint pirate fleet. In the castle, you can play for a day, or spend a day in a daze, blowing the sea breeze, this is the best place to take pictures, the years have left countless mottled marks on the city wall, rusting cannons, and the blue sea water wrapped in huge waves in the distance. It is easy to let people enter the space-time tunnel of Siyuxuan. See the world at the edge