1. Begin in the Tyras Camp and speak to Linford to accept his challenge.
   
   
   
2. Exit the camp to the North and travel through the Tirannwn Forest to the Arandar Pass. Note that it is best if you bring a Tirannwn quiver (2, 3, 4) in order to not fail the tripwires.
   
   Click the above image to enlarge!
   
   
3. At the end of the Tirannwn Forest you will reach the Arandar Pass. Follow the path, using the 2 shortcuts if desired, and travel through the gate at the Northern end.
   
   
   
4. From here, run East toward East Ardougne and walk North across the bridge just South of the Fishing Guild.
   
   
   
5. Once over the bridge, continue East to Catherby. Here you have an option. If you have built the Hidey-hole near the Taverley lodestone, you can click on the rock at the top to scale the rocks to the other side. If you brought a Mith crossbow (or better) and Mith grapple you can still climb over the rocks here.
   
   If for some reason you cannot or do not wish to travel this way, you can also enter the cave to the North of the beach and travel through/on the Mountain to continue. Be aware that you will need to have completed Fishing Contest in order to travel this way.
   
   
   
6. Now in Taverley, continue even farther East. Past Falador, the Barbarian Village, and through Varrock. On the far side of Varrock, travel slightly North as you go East until you reach Paterdomus. Here, the fastest way to continue is to climb down the Saradomin statue shortcut, but you can also go through the basement if necessary (via the "dungeon" North of the Temple).
   
   
   
7. After crossing the river Salve, you will need to head South through the Mort Myre swamp. If you have obtained the shortcut from Temple Trekking, make sure to not use it as this will disqualify your run. To to not use it, choose "Open Gate" instead of "Quick Travel" when entering the gate into the swamp.
   
   
   
8. Once through the swamp, go East to Mort'ton then South to Burgh de Rott. Here, you will need to board the boat to the South East of the city and take it to Meiyerditch (option 2).
   
   
   
9. Arriving in Meiyerditch, jump to the rocks then climb up them. Walk along the ledge toward the North until you reach a part in the floor where you can climb down.
   
   
   
10. Now on the ground, walk slightly North and climb over the wall rubble to the East. Walk North along the Western wall (that you just climbed through) until you reach the most North West house you can enter. The door will have an odd mark on the outside and a Myreque symbol on a panel of the North wall.
    
    
    
11. Climb up the shelves to the East of the symbol. On the second floor, crawl under the Northern section of the East wall then jump to the floorboards in the building to the East and climb down the ladder.
    
    
    
12. Once again on the ground floor, go through the door to the East - you will see a Myreque symbol on the wall North of it. In the next building section, walk out the door to the North, past the diagonal wall, and enter the door to the East of it - this will have another symbol on it. Once in this building, enter the door to the South and climb the ladder.
    
    
    
13. Climb the shelf on the South East side of the wall you are standing next to then climb down the shelf on the North East corner of the building.
    
    
    
14. Next you will need to make 3 separate jumps before climbing down a ladder - North, North, North East.
    
    
    
15. Once more on the ground, exit the door to the East then walk North to the building with the fireplace and climb up the ladder.
    
    
    
16. Walk to the West side of the building and jump the wall. From here, climb to ladder to the North and return to the ground for the final time.
    
    
    
17. Exit out the South side of the building then run directly North until you reach the wall to Darkmeyer. Make sure you are wearing your House Drakan set (hood, top, trousers, boots) if you do not wish to be attacked, then squeeze through the grate and into Darkmeyer. Note that the entire set must remain worn or they will begin to attack you, even if you put it back on.
    
    
    
18. You are now in the home stretch. Simply travel through Darkmeyer to the castle and enter it. Do not enter Vanstrom's Mansion, to the South, or your entire trip will have been for naught.
    
    
    

You should now get a pop up telling you that you have completed the Miscellaneous Achievement "Great Gielinor Run". Congratulations!