The International Rose Test Garden was begun in 1918 and is the oldest continuously operated test garden in the US. Rose plants from all over the world are sent here to test for characteristics that would make a good commercial rose. It has been in its current location in Washington Park since 1928.
Washington Park, and the Rose Garden, rise above the downtown area on a hillside facing east, with a view of iconic Mt Hood.
If you are ever in Portland in June or early July you really should spend an hour (or more!) in this garden! It is sheer beauty.