The Archaeology Department holds some 400 000 collection items, which comprises approximately 90 percent of materials obtained from Latvian archaeological monuments. These ancient artefacts are dated from 9000 BC until the 18th century, amongst which many are unique collections, which no scholar of European and Baltic history can do without. The most significant of the stone age collections are the collection of bone and antler tools from the Lubana Lake Settlement—a fisherman’s grave site of European significance; and collections from the Lubana Lake valley and Sārnate settlements. The iron age is represented by the widely researched Daugmale, Talsi, Mežotne, Tērvete, Asote un Ķente castle hills, as well as collections from the Salaspils Laukskola, Lejasbitēni, Grobiņas and Boķi grave sites. Especially notable is the collection of preserved wooden artefacts from the Āraiši Lake Fortress. The most significant of the medieval collections come from stone walled castles at Cēsis, Koknese and Ikšķile, and from cemetaries in Mārtiņsala and Dobele. Unique also is the largest archaeological textile collection in Europe. The Archaeology Department also holds documentation of archaeological excavations. The National History Museum of Latvia is the only museum in Latvia to hold in its collection surveys and other materials related to archaeological excavations pre-1940.