David Van Gelder Octagon House
 The David Van Gelder Octagon House also known as Springside is located at 21 Walnut Street in Catskill New York. The brick house was built in 1860. It is architecturally significant as an example of an octagon house. The eight-sided plan was made popular in the mid-19th century by phrenologist Orson Squire Fowler. He called the floor plan a superior plan. It includes four large square rooms and four small triangular rooms on each of the two floors.