Tsugaru-Fukushima Castle was the biggest castle in the Tohoku region until modern times. It had a 650,000-square-meter outer ward and a 40,000-square-meter inner ward.

Within the site there is evidence of pit dwellings, outer and inner moats, mounds as well as gate and wall pillars that date to ancient or medieval times.

The castle was the base of the Ando family, which controlled the port of Jusan. Excavation in 1992 revealed that the castle was a full-dress castle with solid mounds and large moats. Moreover, despite an accepted theory, no medieval relic was found predating the 11th century. So, it is likely that Fukushima Castle was built in the 11th century and the inner ward was where soldiers were assembled and some rituals were held.

Facing the Sea of Japan in Kaminokuni, Hokkaido, are the remains of a medieval fort-mansion ('tate'). The fort comprised three halls: Hanazawa, Suzaki and Katsuyama halls, all of which are located in Kamino and which have been designated as an important asset of Hokkaido. The remains of Katsuyama hall, the largest of the halls, have helped solve several mysteries about Hokkaido in the middle ages, following excavations and studies of important artifacts since 1979.

Katsuyama hall was built by the father of the Matsuyama clan, Takeda Nobuhiro. In 1457, he overpowered the local Ainu people, and built this fort-mansion as a feudal residence. Excavation of the hall ruins revealed a trench, the remains of a dwelling and some crockery, as well as records showing that more than 200 people of both Japanese and Ainu race lived together here. Such evidence of racial harmony has drawn a lot of attention.

Some 45% of the ceramics and pottery unearthed here was made in China, which shows that there was active trading and exchange with China.

The Kaminokuni fort-mansion is a very important ruin, which not only has an aura of romance, but has helped historians fill in missing links in Hokkaido's past.

Ishibutai Tumulus is located in the village of Asuka in Nara Prefecture. The tumulus is made of 30 big stones.

Ishibutai Tumulus was built in the 6th century and is one of the biggest of its kind in Japan. It's about 7.7m long, 3.5m wide and 4.7m tall. The passage inside the tumulus is about 11m long and 2.5m wide. The weight of all the stones is 77 tons!

It is believed that the tumulus was the grave of Soga-no-Umako. According to one theory, the mound was tiered because of people's anger toward the Soga clan.
  
In 1933 and 1935, Kosaku Hamada (from Kyoto University) and his colleagues carried out excavation and research here. But, most of the mortuary goods had already been stolen and only some pieces of stone coffins were found.

Ishibutai Tumulus has been loved by many people as a sightseeing symbol of the Asuka region. During daytime, the tumulus is open to the public and you are allowed to enter under the stones.

In Nagai, Yamagata Prefecture, there is a museum dedicated to archaeological sites excavated in the vicinity. The museum itself is in Jomon Village at the foot of Mt Nishi, an area peppered with many ancient sites from the Jomon period.

Extensive research in Showa 52 led to the recognition of the site as an ancient area of habitation dating to the paleolithic Yayoi period. Inside the museum are clay figures and artifacts, while outside on Kodai-no-Oka (Hill of Antiquity) in the center of the village are gigantic clay figures. Visitors can also experience 'camping' inside a restored pit dwelling.

The resource center was built with the idea of preserving the surrounding mountains, rivers and hills, and is populated with many rare animals and plants. Camping in the autumn, when the leaves turn, is also popular.

Shirihachi-date is a medieval fort at the top of a 180m-high hill. The remains of moats, hillside fencing and earthen bridges can still be seen still today.

Excavation has revealed Chinese ceramics dating from the late 13th century to the late 15th century. Of particular interest, these include a celadon 'peony incense burner', which is said to be the most excellent ceramic ever found in Aomori Prefecture.

In 1978 and 1979, excavation revealed 1,800 relics including moats and daily ware, which gave new insights into Tsugaru in medieval times.

Today, the prefectural history museum exhibits valuable relics relating to trade in east Asia. These suggest that Aomori was not an isolated region at all.

Namioka Castle was built by the Namioka Kitabatake Clan in the 1460s. The clan prospered in the early 1500s when it interacted with Kyoto and built temples and shrines.

But trouble within the clan in 1562 weakened their power base and in 1578 Ora (Tsugaru) Tamenobu attacked them and the castle fell. For the following 400 years, the castle remains were used as fields for growing rice, etc.  On 10 February, 1940, the castle was designated as Aomori prefecture's first national historical site.

The castle's 8 buildings originally spread out like a fan, and were divided by dual moats 20m wide and 5m deep. There were pathways on clay walls. These unique constructions were intended to make the castle more maze-like and to protect it from enemies.

Moreover, more than 40,000 excavated articles have been found on the site, including dishes, cooking equipment, weapons, agricultural tools and artefacts for everyday and religious uses as well as architectural relics.

Kanenokuma ruin is a 'funbo-iseki' (tomb ruin) located in Hakata-ku, Fukuoka-shi, Fukuoka Prefecture. It is sited on a 30m-high hill. So far, 348 'kamekanbo' (burials in large jars), 119 'dokobo' (burials directly into the ground) and 'mokanbo' (burials in wooden coffins), as well as 2 'sekikanbo' (burials in stone coffins) have been found here.

A huge amount of kamekanbo were children, indicating that this was the preferred form of burial for children. Many bodies reveal the custom of tooth extraction. Across 400 years, from about 200BC to 200AC, the Yayoi people used this burial site as a public graveyard. It can also be seen that it was a graveyard specifically for common Yayoi people, because no riches such as mirrors were found with the bodies, showing that no people of power were buried here.

Today, Kanenokuma ruin is an historic park. Many of the coffins, including dokobo and kamekanbo, are exhibited in a specially constructed building over the site and in the same condition where excavation has taken place. In 1972, Kanenokuma ruin was designated as an historic site of Japan.

The main deity at Izumo Shrine in Shimane Prefecture, is known as the god of luck, peace, relationships, agriculture andmedicine. Within the grounds of the shrine, are structures built in the ‘shinkoden’ style, which means ‘luck from god’. They are two-storied and include the treasure hall, which exhibits treasures that prove the development of the Izumo Shrine. The main building, which is designated as a national treasure, is now 24m high, yet it is said that it was once twice the height, at 48m. Excavation in progress has proved this, with the discovery of a  gigantic column on the site. On March 19,  2007, the Shimane Museum of Ancient Izumo opened just beside the shrine and exhibits the original column of the main sanctuary. About 600,000 people visit the shrine during the first three days of the New Year