Judges 6:11 (ESV)

11 Now the angel of the LORD came and sat under the terebinth at Ophrah, which belonged to Joash the Abiezrite, while his son Gideon was beating out wheat in the winepress to hide it from the Midianites.

The exact location is unknown, but Judges 6:15 suggests it was in the territory of Manasseh. That would mean it was somewhere in the hill country between Ephraim’s territory and the Jezreel Valley.1