The Lower Terrace was built in the 1950s when Carl and Olga Milles returned to Europe after 20 years in the USA. They spent the winters in Rome and many summers at Millesgården. The Lower Terrace was inspired by the Italian piazza; Carl Milles wanted an open, paved square with tinkling fountains and room for lots of people. The terrace?s red-toned sandstone is made of quartzite from Älvdalen.
When Carl Milles extended Millesgården in the 1940s and 1950s, he wrote that he wished to create a meeting place for people and his plans were all but conventional for a museum park. He wanted to create rinks for ice and roller skating, a swimming pool, as well as a waterfall. Many of his plans were never realised but the waterfall was built. It is the incavation in the wall facing Lake Värtan. Above the walled ledge on the outside of the wall, the water was to gush and fall ca. 30 metres towards Lake Värtan, where Poseidon would stand and keep watch. The waterfall was never switched on.