Beacon was apparently once known as the hat capital of the United States. These are the ruins of one of the factories that made the hats. Demolition was supposed to have started in 2012, but if that’s the case it doesn’t seem to have progressed very far.
According to Tom Rinaldi and Rob Yasinsac’s Hudson Valley Ruins site:
The Tioronda Hat Works on the Fishikill Creek in Beacon has been undergoing demolition since September 2011 (or earlier). Begun in 1879, the mill, like many in the area, expanded with new construction in the following decades. The last mill to occupy the brick buildings was the Merrimac Hat Company. In 1949, Merrimac sold the property to Beacon Terminals Corporation, which used the buildings for warehousing. In 1997, real estate developer William S. Ehrlich formed a different company under the name of Beacon Terminal Associates and acquired the former Tioronda Mill and about 20 other properties in Beacon, NY, many of which have remained vacant.
The Tioronda Working Group says that Tioronda means “place of the council fire where the two rivers meet”