Jefferson designed the house based on the principles of Andrea Palladio. Construction began in 1768. Jefferson moved in two years later. He remodelled the house after picking up ideas in Europe. The house is located on a peak in the Southwest Mountains. Its name is Italian for "Little Mountain". Slave quarters were located 300 feet south of the house on Mulberry Row. These quarters were occupied by slaves working in the house. The slaves working in the fields lived in another place. A cabin on Mulberry Row was once the home of Sally Hemings. She was a slave who had a long relationship with Jefferson after his wife died. She gave birth to six of his children. An image of the house has appeared on the United States nickel and on the two-dollar bill. Monticello became a UNESCO World Heritage Site in 1987. It has been owned and operated by the Thomas Jefferson Foundation since 1923.