Capitol Hill is at once the highest point of Washington East and the central point of Old City, the part of Washington built according to L'Enfant's original plan. It houses buildings serving the legislative and judicial branches of the federal government. Beyond them, pretty residential streets are lined with rows of 19C houses, where trendy enclaves are springing up. Towards the east, neighbourhoods in the grips of gentrification are flourishing, signifying a city undergoing changes.