Salisbury Crags definitely has some rather beautiful views.
Around Edinburgh, the Pentland Hills have some fairly interesting terrain and gorgeous views of the city. Within a short drive of Edinburgh you could travel to Falkirk which has a stunning looking boat lift. Alternatively over the Forth Bridge you could travel to Fife and catch some of the cute coastal villages.
Just make sure, depending on when you're coming to Edinburgh, to bring warm clothes. It's a beautiful city but very cold.