Legend of the Past

The four objects have shared spawn points, you can find them in multiple predefined locations over the Timeless Isle. They are rare and have a yet unknown respawn timer but check the locations below frequently and you'll get one of them eventually. You need to find only one for this part of the achievement.

These objects are the officially confirmed way to break into the Mysterious Den, where [npc=71864] resides along with one of the Sturdy Chests.

Verified locations (by myself):

Conjuncted map with all verified spots

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• 47.3-80.8 --- South side of the ramp that leads up to Firewalker Ruins.
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• 55.3-50.3 --- Under the broken bridge, in front of the Mysterious Den.
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• 63.1-45.3 --- On a ledge to the west of the pathway in the Blazing Way area.
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• 55.6-59.3 --- On the top of the hill-spike that connects the upmost pair of Ordon bridges.
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• 50.4-71.7 --- On the stoned area east of the Everlasting Spritewood.
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• 68.4-60.4 --- Near the ruined tower on the east as you pass through the bridge from Firewalker Ruins.
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• 42.8-55.4 --- Next to [npc=73303]'s tribune.
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• 48.0-51.2 --- On a rock, north side of Mossgreen Lake.
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• 25.0-71.9 --- Next to the Alliance camp graveyard.
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• 64.5-72.3 --- On a stump in Croaking Hollow.
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• 55.1-72.9 --- On the northern slump scraps @ Firewalker Ruins.
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• 33.8-54.5 --- At the entrance of Celestial Court (arena).
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• 37.7-41.1 --- On a small rock halfway between the Celestial Court and 3-Breeze Terrace.
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• 39.6-77.8 --- Next to the broken shrine at Pi'jiu village.
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• 65.4-51.7 --- On a rock next to the daily quest giver [npc=73570].
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• 52.2-62.6 --- Southeast of Mossgreen Lake.
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• 32.0-61.5 --- Southwest of Celestial Court.
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• 32.6-32.8 --- On a rock at the west side of 3-Breeze Terrace.
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• 22.4-38.7 --- Next to the Horde camp graveyard.
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/way 47.3 80.8
/way 55.3 50.3
/way 63.1 45.3
/way 55.6 59.3
/way 42.57 55.30
/way 25.04 71.86
/way 49.9 71.7
/way 55.6 59.3
/way 47.3 80.8
/way 55.2 50.4
/way 63.1 45.3
/way 30.7 55.2
/way 55.0 72.8
/way 68.4 60.2

For anyone with waypoints(some are close to each other in case one is more accurate). Thanks everyone that posted extra spots for the info.

The four objects when clicked on grant different 10 minute buffs with visual effects:

• [object=222796]: [spell=147277]
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• [object=223539]: [spell=149349]
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• [object=223537]: [spell=149333]
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• [object=223538]: [spell=149346]