Opinions were divided on the time when the Simen Pagoda was built. Some people thought it was built in the first year (351BC) of the Huangshi reign of the pre-Qin Period and other considered it was built in the 2^nd year (544) of the Wuding reign of the Eastern Wei Dynasty (534-550). In 1972, when the body of the pagoda was under a big renovation, several words built in the 7^th year (611) of the Daye reign were found inside its roof. This unveiled the mystery and determined that it was first built in the Sui Dynasty (581-618). It is the oldest stone pagoda extant in China.

Some 15 meters tall and 7.4 meters in side length, the entire body was built of huge bluestones, with only one layer in a square shape. There is an arch door on each of the four sides and that is why it is called as the Simen (Four-Door) Pagoda. The pagoda is unique for its simple and vivid structure. On the upper part, there are five layers of eaves piled up with stones. Further upward there is a tapered and pointed roof with four corners. On the roof it is a spire carved out of stone. Inside the pagoda, a square central pillar stands in the middle, tall and strong, surrounded by a winding corridor. On the pillar there are four stone Buddha statues sitting cross-legged and with dignified and beautiful faces. They were carved in the 2^nd year (544) of the Wuding reign of the Eastern Wei Dynasty.

In the old times, Buddhist halls and temples stood in great numbers around the Simen Pagoda. Many of the extant cultural relics and historic sites, such as the Zushi Forest, the hall foundation of the Shentong Temple, the large and small Dragon-Tiger Pagodas, etc, all have very high historic and artistic values.

Near the Simen Pagoda and in the ruins of the Jiuta Temple (Nine-Pagoda) in the Lingjiu Mountain, there is a pagoda built in the Tang Dynasty (618-907). It has a single layer and is eight-square. On the top there are nine small pagodas, so it is locally named as the Jiuding Pagoda (the pagoda with nine small spires). The total height is 13.3 meters. On the south side of the pagoda there is a Buddhist room. The sunk panel and frescos on the ceiling are still there. The Jiuding Pagoda has a very unique structure among Chinese ancient pagodas.