The Xiyu Ammunition Depot Military Cultural Park(西嶼彈藥本庫軍事文化園區)

A National Historic Site, was primarily used for storing artillery ammunition.
  
The depot features two types of cave-style ammunition bunkers: single-chamber and double-chamber bunkers, both designed to maintain a constant temperature and humidity. The single-chamber bunkers are built with a triple-layer vaulted roof, while the double-chamber bunkers use a double-layered vaulted wall structure. The double-chamber bunkers were specifically designed to store two types of gunpowder—smokeless and traditional gunpowder. The cave-style ammunition depot uses a double-layered vaulted wall structure. First, an arched tunnel was excavated into the rock layer inside the mountain. The external structure was reinforced with reinforced concrete and a waterproof outer layer was applied. Then, an inner storage space was constructed using reinforced concrete. To preserve smokeless gunpowder, in addition to maintaining a constant temperature and humidity, copper sheets were installed on the ceiling and walls to completely block electromagnetic pulses and moisture, ensuring optimum storage conditions.
  
The earth-covered ammunition depot, on the other hand, is an above-ground structure with exterior walls made of stacked stone. The interior walls are constructed from wooden panels and the floors are elevated with wooden planks to prevent moisture buildup. The roof structure uses a steel truss frame and the roofing is made from traditional smoked black tiles, known as "cultural tiles." A lightning rod is also installed on the roof to protect against lightning strikes.
  
Both types of ammunition depots are rare examples of early Japanese military architecture in Taiwan, showcasing the distinctive construction techniques of the Japanese colonial period. For their historical significance, they have been designated as National Historic Sites for preservation.

Source: Penghu Travel
Image Source: Penghu Travel, Penghu National Scenic Area Administration Court