The best way to get a feel for Belfast's natural setting is to view it from above. In the absence of a private aircraft, head for Cave Hill (368m) which looms over the northern fringes of the city. The view from its summit takes in the whole sprawl of the city, the docks and the creeping fingers of urbanisation along the shores of Belfast Lough. On a clear day you can even spot Scotland lurking on the horizon.
The hill was originally called Ben Madigan, after the 9th-century Ulster king, Matudhain. Its distinctive, craggy profile, seen from the south, has been known to locals for two centuries as 'Napoleon's Nose' - it supposedly bears some resemblance to Bonaparte's hooter, but you might take some convincing. On the summit is an Iron Age earthwork known as McArt's Fort where members of the United Irishmen, including Wolfe Tone, looked down over the city in 1795 and pledged to fight for Irish independence.
To get there, take buses 1A to 1H from Donegall Sq West to Belfast Castle or Belfast Zoo. If you wish to climb Cave Hill start from the public car park just before the gates of Belfast Castle. Take the path that leads up from the car park. After 150m you reach a horizontal path at a T-junction; go right and follow this trail as it continues uphill through the woods. After about 800m you emerge from the trees beneath Cave Hill's eastern crags. Fork left beneath the obvious caves that give the hill its name (signpost); if you keep straight on here, the path continues north for 1km to the Belfast Zoo car park and traverse to the north beneath the cliffs then climb up to a shoulder (muddy). The path then doubles back to the south and follows the cliff tops to the summit.
A little bridge and some steps lead up to the summit proper, an Iron Age fort surrounded by crags. There's a superb view across the city, harbour and lough, with Scrabo Hill and Tower prominent on the eastern horizon, and the rounded forms of the Mourne Mountains far away to the south.
Continue south then west on a broad, well-made trail for almost 1km. At a sharp bend to the right, beside a wooden bench, leave the trail on the left via a stile, and go downhill on a faint path through a field. Pass through another stile at an old quarry and turn left, keeping the quarry on your left. The path then descends more steeply through woods; at a T-junction go left on a better path which leads to the T-junction above the castle car park; turn right here to finish. (Total 5.5km; allow two hours.)