The Union Church of Pocantico Hills is a pretty small church fairly common, though very lovely neo Gothic architecture.
What makes this little church so amazing is that it houses the last work of Henri Matisse. A stained glass rose window that was commissioned by the Nelson Rockefeller to honor the memory of his mother Abby Rockefeller. It is very different than what you would usually expect from a rose window but it does maintain the flower theme of the name.
Matisse was added the the church the Rockefeller family donated many more stained glass windows all created by Marc Chagall. The largest, named the Good Samaritan window, is dedicated to John D. Rockefeller, Jr. Nelson's father. JDR Jr. dedicated his life following his fathers foot steps in philanthropy and spent most of his life giving using his inherited fortune to help make the world a better place and so the story of the Good Samaritan who gave his time and money to help a stranger was chosen for his memorial.