Hearthstone Castle in Danbury, Connecticut, was built between 1895 and 1899. It was listed on the National Register of Historic Places in 1987. It has also been known as Parks' Castle and as The Castle. The property includes four contributing buildings and three other contributing structures. Today, the castle is owned by the City of Danbury and is located in Tarrywile Park. Hearthstone Castle is slated to be renovated into an observation deck.