Based on geology researches, the currently left-alone Taiwan used to be a peninsula linked to Mainland China. Thereafter, because of sagging caused by local stratum changes, a strait 200Km in width occurred and it is exactly what we call the Taiwan Strait. Since then, Taiwan had become an island with oceans surrounded. An English authoritative geologist deduct that Taiwan started to become an island due to sagging roughly in the period from the earlier 3rd century to the late 4th century. 

Just during the period for Taiwan becoming a peninsula, Paleolithic human beings had stepped into Taiwan from remote southern China areas. For the latest decades, archeologists have found numerous large mammal fossils such as rhinoceros and elephants. Also, in numerous areas, there are also several black pottery and painted pottery cultures discovered. 

It is generally supposed the mainland China cultures were transmitted from Penghu to southern Taiwan, northern Taiwan and then eastern Taiwan finally. Thus, the traces of Paleolithic cultures must exist in the seashore areas of southern Taiwan and then extend to eastern Taiwan. It can be deducted that there must be some Paleolithic culture traces in Kaohsiung. However, because the Touziyuan area is now classified as the military zones, there is no any Paleolithic relic found till now. As for the Neolithic culture relics, before the Touziyuan area was classified as a military zone, there had been several relics discovered. There can be 3 culture layers separated roughly: 

1. Earlier Cord Ornament Pottery and Net Ornament Pottery Culture Layers:

Cord Ornament Pottery cultures were distributed around Taiwan. Cord ornament pottery is featured with cord ornament on the surface, a pottery designed with cord ornament. It is originally distributed in mainland China and Indochina peninsula .  However, at the Touziyuan area, there used to be some culture remains of intact Cord Ornament Pottery and Net Ornament Pottery found. In addition, there were also some stone axes and grinding wares found such as stone arrowheads and stone knives discovered. The ages were roughly the period from BC 4200 to BC 7000, a period equal to the earlier Neolithic age.  Thus, there were human beings living in this area 4200 years ago.   

2. Middle Painted Pottery Culture Layers: 

The Painted Pottery Culture is mainly distributed in the middle China and it is also called Yanxiao Culture, while Black Pottery Culture is mainly distributed over the seashore areas and it is also called Longshang Culture. Based on the saying of archaeologists, both Black Pottery Culture and Painted Pottery Culture were developed in the same period but distributed over various areas. In Taiwan, there used to be several painted pottery and black pottery of cultural relics found and they mainly were stone knives, sharp edges and stone axes roughly during the period of 1200 to 4000 years.  They belong to mainland China culture systems with close relation to Yanxiao Culture and Longshang Culture.

3. Late Red Sand Pottery Culture Layers:

The red sand pottery layers are distributed in the southern Taipei.  The sites are Tainan Wanliao, Niuchozi and Fongbitou nearby Kaohsiung city. The age is roughly a period from 300 years to 1200 years ago.