Andumi Oak tree - a cult site - lies in the south-eastern part of Lībagi Parish, about 2 km south-west of Mežīte Hillfort. To find the oak, follow the Lībagi-Mērsrags road and take the first forest track on the right after Mežīte Hillfort. From the turn-off, follow the track for about 2 km, until you reach a forest cutting - the site of the great oak.
The oak is 5.35 m in girth and 21 m high, with a crown measuring 25×35 m. The place-name ‘Andumi' (Andemen, Andeman) is mentioned several times in historical sources from the 14th century onwards. Indirect evidence of the former existence of a major cult centre here comes from a document of 1476 concerning Strazde, attesting the sale by Hans Schwenk to Werner Buttlar of a holy grove near the Latvian village (Lettendorpe), which was next to the Riga road.
According to evidence collected in the 1920s by Talsi teacher and regional historian T. Dzintarkalns, there was once also an artificial cairn in Andumi Forest, regarded by local people as an ancient sacrificial site. It was said to have been the abode of the priest Tors and his helpers, a figure who wielded considerable power in the area. It is possible that in the Middle Ages the area around Andumi was actually more densely populated and has declined over the centuries as a result of war and epidemics. There is also a story that there was a manor near the oak in ancient times, the oak being known accordingly as the ‘Old Manor Oak' (Vecmuižas ozols).