The Horn

The Elder Horn is an Elder God artefact of which nothing significant is known about. It was found by Guthix in Gielinor shortly after he discovered it, in the First Age. It was one of the many artefacts that granted him the power he was known to have.

Under Guthix's possession
Guthix was travelling between dimensions with cuts from the Elder Sword just after he achieved godhood unintentionally, by killing the god Skargaroth with it. At some point, he found Zanaris, the moon of Gielinor. He could see Gielinor from it, which looked luxurious and explendid. With curiosity, he made his way to Gielinor and was overwhelmed by its beauty. He started exploring it and soon found many elder artefacts, incluiding the Stone of Jas, the Elder Horn and the Elder Staff (which would be later known as the staff of Armadyl). He used the elder artefacts and created gateways and runes for mortals. After seeing the devotion of mortals to him, he decided that his absence and removal of proofs of his existance would make them forget him and let them live their lives with the maximum freedom, he then hid all the artefacts, incluiding the horn and created his home deep down the earth and slept.

The Elder Crown
The Elder Gods also created an artefact that worked differently from the others. It would serve only as an locator of all the artefacts, but in order to also locate it, all the elder artefacts posses the ability to locate the Elder Crown, incluiding the Elder Horn. The Elder Crown has been in Saradomin's possession for over 10,000 years, and still is today.

Suspicions
There are many powerful horn-artefacts scattered in Gielinor, many are thought to be the Elder Horn, but it was never confirmed.

The Frostenhorn
The Frostenhorn is a powerful relic used to intensify most things, incluiding power and climate. It was mostly in the possession of Zarosians through the ages. It lied inside the fortress of Ghorrock entirely during the Fourth Age and almost during the all Fifth Age. It intensified the climate of the cold region and froze the fortress, allowing its preservation. The area around it was also affected by the the intensification, even the Ritual Site.

Quin's horn
The seasinger Quin, the most powerful seasinger of the Eastern Lands has in possession a horn-artefact that allows her to use her seasinger power on any sea creature anywhere in Gielinor, sealing the entire sea to her will. The seasinger powers generally only affect only an area of the world, but with the horn, she managed to reach all the areas of the world. It is possible that it's the Frostenhorn's other part, as it also intensifies her power. In either way, both are the most popular suspicions that one of them, or both, are the elder horn.