Outlying tops of Arthur’s Seat, Edimburgh

Start : Blackford Pond (EH10 6BJ) Grid ref : NT 25542 70979

(S/E) Start from Blackford Pond, exit the Park by the Charterhall Road Gates. Cross over to climb Oswald Road. Once across the bridge over the suburban railway line, turn right down Mortonhall Road. Cross directly over at Blackford Avenue to walk along West Relugas Road and straight on along Relugas Road. (A)

(1) Leave the Pow Burn culvert by turning left up Findhorn Place. Cross St. Albans Road and turn right along Fountainhall Road. Cross directly over Mayfield Road to follow West Mayfield. Soon turn left up South Gray Street. On reaching a cross roads and the building of the former Bartholomew’s mapmaking firm, turn right along Duncan Street. (B)

(2) Soon, turn left around Blacket Place. At the Old Dalkeith Road, exit through more old entrance pillars, beside the old porter’s lodge. Use the pedestrian crossing. Turn left along the pavement to arrive at the Royal Commonwealth Pool.

From the main entrance to the Commonwealth Pool pass alongside its left-hand side to exit out onto Holyrood Park Road. Turn right towards the Park. Keep right through trees to pass to the right of the roundabout and across the roadway. Head up the grass.

(3) Aim slightly left, as the path divides, for the summit of Arthur’s Seat. Cross Queen’s Drive. Keep on up. Pass the end of the Radical Road. Keep aiming for Arthur's Seat. Although the route climbs Salisbury Crags, do not turn left before the col. Instead, crest the low point in the Crags, and descend slightly before discovering, around a corner, a flight of 58, steep, well-constructed steps to the left.

The footpath now rises diagonally on a rising traverse. Eventually, arrive at a good viewpoint way above the flats at Dumbiedykes and directly opposite Calton Hill. The summit of Salisbury Crags, to the left, can be easily climbed from here, if desired. To descend turn right, and head down towards Haggis Knowe and St Margaret's Loch. Pass above the old Camstone Quarries (where sandstones, shales and cement stones exhibit well-developed sun-cracks, ripple-marks and worm-tracks).

Note, on the sky-line, across the valley a bare tump above St. Anthony's Chapel, which the route, in due course, visits. It forms one of a succession of nineteen lava flows that make up Whinny Hill.

Head down towards to the right-hand base of Haggis Knowe. Take the path leading up to St. Anthony's Well, but soon turn left up Haggis Knowe. Its top provides an excellent, panoramic view across the city and over to the Firth of Forth. Return to the St. Anthony's path.

(4) Drop left towards St. Margaret's Loch. Follow the narrow footpath along its right-hand bank. Beyond the loch keep right through trees. Emerge onto Queen’s Drive. Turn right. In about 200m, by a lay-by, the slope on the right eases and a good, broad, grassy footpath angles gently upwards. Follow this Quarter Mile path as it rises more steeply while smoothly curling to the right. Rise to reach a slight col. Mount the bare, rounded tump on the right, with good views across the loch. (C)

(5) Descend to the col. Traverse gently around the southern side of Whinny Hill. First head for the prominent, 165 ft, spire of Joppa Parish Church. Next aim for the distant chimney of the Anaerobic Digester, and characteristic white plume (of small particles in the form of water droplets) at the Millerhill recycling and energy recovery centre (where Edinburgh's recycled food waste produces enough electricity to ‘boil 1.75 million kettles'). Finally, head down towards the South end of Dunsapie Loch.

(6) Cross Queen’s Drive and make for the gentle shoulder, to the left of Dunsapie Crags, with trees further to the left. Rise up either directly or following zigzags to arrive at the top of Dunsapie Crags. Across the Loch, on the eastern flank of Arthur's Seat observe a well-preserved flight of ancient cultivation terraces. Descend towards the car park at the end of Dunsapie Loch. Turn left along Queen’s Drive.

In 900 m, when directly due south of Arthur's Seat, a small gap in the boundary wall gives access to the crags immediately above Samson's Ribs. This point marks the site of the southern zenith station used in measuring the “Weight of the World”. Rise to the right, and follow the footpath above Samson’s Ribs.

(7) On re-reaching Queen’s Drive, immediately descend left towards the roundabout on Duddingston Low Road. Pass to its left to return to the entrance to the Commonwealth Pool. Follow the outward route back to Blackford Pond.(S/E)

Start : Blackford Pond (EH10 6BJ) Grid ref : NT 25542 70979

Parking : There is a small car park at the starting point of the walk.

Find out more about Roy's Edinburgh Walks here.

Find out more about "Weighing the Earth using Arthur's Seat" here.

(A) The route is following a shallow valley between the Blackford Hill and Church Hill / Greenhill ridges. But where is the valley-bottom stream? Since the 1850s the Jordan / Pow Burn has been culverted and flows underground. For example, it runs between the trees along the right-hand (southern) edge of Relugas Road and the immediately adjacent housing. Nevertheless, short, open stretches of water can still been found in the grounds of Woodburn, Astley Ainsley and Blackford Bank. The water flow can be heard at a manhole cover, near a directional change in the culvert, at the entrance to Relugas Gardens.

(B) Note the fine facade fronted with 12 Corinthian pillars each a monolith of Craigleith stone, brought from Falcon Hall on its demolition. Pedestrian lights lead across the main A701 to allow access through the entrance pillars of Blacket Avenue. The Blacket gates used to be closed daily at dusk to preserve security and amenity in this early, select, suburban, gated development.

(C) Just below here, above St. Anthony's Crags, a zenith station was established in 1856 to “Weigh the Earth”. An impressively correct density of 5,316 kg·m−3 was obtained. Observing stations were constructed to both the north and south of Arthur’s Seat and the deflection of a plumb-line (inwards towards the mountain) accurately compared with the true vertical (zenith), as determined by star sightings in the night sky. The tiny difference in the deflections, 4¨21 seconds of arc (roughly the diameter of a pinhead at distance of a football field) then gave (after a little maths) the Earth’s mass as a multiple of that of Arthur’s Seat.