The tomb of an ancient family discovered after 1,800 years in China. See the treasures inside

An ancient family from eastern China built three underground tombs, filled them with treasures and buried their loved ones. The burials took place century after century. Thieves broke in. Eventually the site was forgotten.

But not anymore.

Archaeologists in Rizhao City have unearthed a partially damaged mound in preparation for the expansion of a nearby park, the Institute of Archeology of the Chinese Academy of Social Sciences said in a May 11 press release shared via the China Archeology Network.

Underneath, archaeologists discovered three tombs from the Han dynasty, a period that Britannica says spanned from 206 BC to 220 AD.

Discover more archaeological discoveries

What do we learn from the past? Here are three of our most eye-catching archaeological stories from the past week.

→ Report on archaeological site theft leads to ancient discoveries in Peru

→Medieval treasure belonging to legendary crook discovered in Polish mountains

→ Rare collection of centuries-old fabrics and shoes discovered in Poland. Look at

The 1,800-year-old tombs were similar in style, with two burials in each and sloping passages to the entrances, the institute said. Inscriptions in two of the tombs had the same surname, Huan, indicating that the complex probably belonged to one family.

Two of the ancient tombs were looted, archaeologists said. The wooden coffins were left in the graves but very few objects remained.

The third ancient tomb, however, was well preserved and relatively intact, the institute said. A photo shows this tomb, called M3.

The main burial chamber of Tomb M3 had two rooms connected by miniature windows and doors. A photo shows these unique wooden windows. Archaeologists said the residential style suggested the tomb contained a husband and wife.

Archaeologists also found more than 70 artifacts inside the tomb. Photos show some of these treasures, including an iron sword, bronze mirrors and stacks of several types of pottery.

Around one of the wooden coffins, archaeologists discovered the remains of a coffin cart, a structure used to transport the coffin to the grave, the institute said. They described it as exquisitely crafted and a rare find.

Archaeologists have described the 1,800-year-old family tombs as a significant and important find. Finding the same last name inscribed in multiple graves is rare, the institute said.

Excavations at Rizhao began last December and ended in January. Rizhao, sometimes translated as Jihchao, is a city in Shandong province along China’s east coast, about 400 miles southeast of Beijing.

Google Translate and Baidu Translate were used to translate the press release of the Institute of Archeology of the Chinese Academy of Social Sciences.

A gardener weeding a raspberry patch unearths a 4,500-year-old tool in Poland. To see the

Medieval castle — “witness to centuries of change” — excavated in the UK. To see the

1,600-year-old indoor swimming pool discovered in ancient Roman ruins in Albania, photos show