The Hillforest Mansion, also known as the Thomas Gaff House, is located at 213 Fifth Street, in Aurora, Indiana.

Hillforest was designed by Isaiah Rogers and built in 1855 for Thomas Gaff (1808–1884), a Scottish born businessman who moved to Aurora in the 1840s.

Gaff and his siblings had a large number of business interests, including alcohol production (distilleries and breweries), railroads, and steamships.

The design of Hillforest is evocative of the steamships that plied the Ohio and Mississippi Rivers in the 19th century.

[3] The property remained in the Gaff family until 1926, when it was purchased by William Stark, a furniture manufacturer.