A Map of the Aiel Three-Fold Land
The Three-Fold Land is one of the more mysterious regions in the series. Technically, we are told it is unmapped territory - if the Aiel have mapped it or parts of it, none of these maps have ever made it into the hands of Westlands scholars and printers. Contrary to the assertion in The World of Robert Jordan's The Wheel of Time (written from the perspective of in-series scholars rather than from a neutral and all-knowing perspective) it is possible that such maps exist: at the battle of Cairhien the Aiel clan chiefs show familiarity with the planning of battles on maps. However, Cairhien was for them foreign territory - unknown territory to many (only four clans have taken part in the Aiel War), and it's not impossible they rely strictly on their intimate knowledge and memory of the terrain for battles and raids in the Waste.
In any case, we know the 'Wetlanders' themselves have no map of the Aiel Three-Fold Land they call 'The Waste' - which for most in the Westlands is Terra Incognita, like Shara and Seanchan. The mysteries surrounding the exact geography of the Waste is reflected in The World of Robert Jordan's The Wheel of Time, which has two rudimentary maps on which the Aiel Waste appear (the map of Shara and the world map) but on which no geographic feature described in the books is identified. In keeping with this theme, it's possible no precise map of the area is included in Harriet's Encyclopedia (Jordan reputedly wasn't in favour of including maps of the world, Shara and Seanchan in the Guide, it's his publisher who convinced him to allow them)
Through the events in the series (mostly in The Shadow Rising and The Fires of Heaven) we know of several locations in the Waste: Rhuidean in the valley below Chaendaer; Imre Stand - a very small watering hole on Taardad land; Cold Rocks Hold, the home of Rhuarc's sept in a canyon; Alcair Dal (from the O.T. Al'Cair Dal, ie: The Golden Bowl), a circular, bowl-like canyon ('not golden' at the time the characters visited it, but it may appear so at sunrise or sunset) at which meetings between clans are often held - perhaps because the great acoustic properties help keep the various participants at safe distance from each other - as well as the names of several sept holds. We are given precious few clues to locate any of them on a map, in most cases none at all.
The location we learn the most about (and the only one I took a guess at positioning on the map) is Rhuidean. We know Rhuidean is situated in the valley below the mountain Chaendaer. Chaendaer is not part of a chain, but the valley is surrounded by various jagged chains in the distance. The mountain is located West of the city- we know this, notably, from descriptions by Nynaeve and later Rand: from Chaendaer, the sun can be seen rising behind the city, over jagged peaks:
"Between one step and the next she was suddenly on a mountainside, with a harsh sun rising over more jagged mountains beyond the valley below, baking the dry air. The Waste. She was in the Waste." (The Shadow Rising, A cup of Wine - Nynaeve POV)
The way out of the valley and into the heart of the Waste is to the North West. The clan that live closest to Rhuidean is the Taardad. Imre Stand, a watering hole, is located less than a day's travel from Chaendaer - so perhaps up to 10 leagues, probably less - maybe much less (it's fairly tricky to evaluate the speed of travel in the Three-Fold Land, harder than to average travel on horses, from various clues that introduce variations in the distance they can cover each day: how many days in a row they travel, if they have plenty of rest and food, if they are on roads or cross-country etc.). Aiel are fast walkers, but they had peddlers wagons progressing on tricky terrain to account for etc. Cold Rocks Hold is located in the same direction from Rhuidean (North West), eleven days from Imre Stand. Alcair Dal is three to four days North from Cold Rocks Hold in high jagged mountains that can be seen over a day afar. Travel from Rhuidean to the Jangai Pass took thirteen to fourteen days, at fast speed. There are many more mountains and rock formations in the Waste - Rand often describes it as crisscrossed with sharp and rocky hills, broken rock formations and mountains; Aiel holds are often hidden in them. Those formations would trap winds and offer a bit more moisture, and water holes. The Aiel Waste is more similar to areas in Arizona, the Grand Canyon or parts of Tunisia than to the deep desert like the Sahara (that would be, presumably, more like the Termool area).
The location of Rhuidean on the map is thus very approximate - based on the length it took to travel (at pressing speed as they hunted after Couladin) from there to the town of Taien at the opening (on the Three-Fold Land side) of the Jangai Pass, and on the description of the area. The map of Aiel Waste in The World of Robert Jordan's The Wheel of Time (one of the few not done by RJ's regular map artist Elisa Mitchell, but rather by John M. Ford) is however imprecise in its depiction of the mountain ranges and distances).
The lands of Tardaad lay closet to Rhuidean, to the North West. The Jindo sept of the Taardad lives beyond the Nine Valleys' land, and the lands of the Shaido clan are farther away in the same direction. Two septs of the Chareen, the White Mountain and the Jarra, are the closest enemies of the Taardad from Imre Stand. The Goshien lands are next, somewhat farther, enough to make Aviendha doubt they could have been responsible for the attack at Imre Stand. The Nakai's lands are the ones farthest away from this general area of Taardad lands, Alcair Dal and Rhuidean, though we don't know in which direction.
To the South, above the coast, is the Termool (probably old tongue, for 'The Waterless Sands') a totally desert area, so barren, desolate and dry even the Aiel do not travel it according to the Guide. They must travel very near, however (perhaps close to the Spine of the World), as we know they go South to Stedding Shangtai (home of Loial), located in the mountains above the Drowned Lands of the peninsula on which the city-state of Mayene stands. Beyond the Termool is the Sea of Storms. An archipelago of Sea Folk Isles lay at about equal distance from Mayene and Shara, several hundred leagues South - just above the equator line. It is one of the two (major) Sea Folk archipelagoes that have never been named anywhere.
To the South East is The Great Rift, atop of which begins the land most commonly called 'Shara' in the series (the various names are probably those of regions or provinces - or even cities - on this continent). To the North East is another mountain range, delimiting the border of the Three-Fold Land and Shara: the Cliffs of Dawns. To the North, the Aiel Waste is bordered by the Mountains of Dhoom and beyond them the Blight. The Waste is named by Shadowspawn Djevik K'Shar, The Dying Ground in the Trolloc tongue. To the West, of course, is the Spine of the World - mountains with no counterpart in the real world (Jordan once described them as how the Himalayas might be, if they were still only 3000 years old, not up to 50-70 millions years old). We know of at least two passes between the Aiel Waste and the mainland: the Niamh Passes at the South-West border of Shienar, and the Jangai Pass leading into Cairhien below the Kinslayer's Dagger mountain range and the river Gaelin. There remain two Cairhienin towns in the Jangai Pass, remnants from the period extending from 566 NE to 976 NE, during which the Cairhienin were granted by the Aiel a right of passage through the Waste to reach Shara, a way dubbed The Silk Path (the right was a gift to honour the memory of the Cairhienin's distant ancestors sharing their water with the Da'shain Aiel on their way to the Waste): Selean is located at the western end of the pass and Taien at the eastern end. Both towns are small, with few inhabitants and both suffered the ravages of Couladin's Shaido as his warriors took the Jangai Pass into Cairhien. Rand brought the refugees to the city of Cairhien with him, meaning those towns are now abandoned. The RPG book 'The Prophecies of the Dragon' had this bit of back story that House Mecandes' domains were in this area and their wealth based in the silk trade, before the House fell apart as a result of the Aiel War. Robert Jordan rejected this as erroneous: there is no such House in Cairhien, the blue sister Cabriana Mecandes was rather, as the name made obvious, Tairen.
The trajectory followed by the Silk Path is unknown, beyond it's beginning in the disused road that still leads from Cairhien to Selean, following the Gaelin. The most likely arrival point in Shara would be in the more accessible, lower area between the Cliffs of Dawn and the beginning of the Great Riff. Nowadays, only the Aiel themselves trade there, and only for their own needs. The Sea Folk take care of all trade between Shara and the Westlands.
About the Map:
The map is based on layouts for the 'Big Map' by Elisa Mitchell and the map of Shara by John M. Ford. The chronology information follows the priceless Wheel of Time chronology site, Steven Cooper's Tellings of the Wheel