Little is visible of the spectacular Milford-Newtown-Turner earthwork cluster today because of 19th century destruction. A little farther up river, and still intact (though on private land), is the decidedly strange hilltop enclosure at Fosters. A riverside gazebo (behind an unusual stone tavern building, beneath the high US 22 bridge) offers views of the wooded hilltop site across the river.
In 1890, archaeologist Frederick Ward Putnam came from Harvard University to investigate here. He called it “a singular ancient work” because he found that the walls were loaded with heavily burned stone, earth, and clay. Archaeologist Bob Genheimer explains:
What’s unique about Fosters really is the use of this burned clay, and burning really doesn’t do it justice: it’s heavily vitrified clay. So if you pull back the leaf litter, and some of the debris, what you see is bright orange. They have capped these walls with this highly vitrified soil, burned clay.
It seems this soil was fired in ovens at the site. Archaeologists found flues that could have controlled the flow of air, permitting very hot temperatures. Similar forms have been found at other sites, including Turner.