Shipwreck Graveyard

The Ship Graveyard was a place where ships were lost, abandoned, and hidden.

Description
But it’s not completely hidden to all Vikings; Trader Johann uses this secluded spot to store all his goods and wares. The graveyard also houses another secret, the Dragon Eye.''
 * ''In the fog surrounding the archipelago lies an abandoned graveyard of ships where unlucky sailors have lost their bearings and crashed.

Dragon Eye of the Beholder, Part 1
At some point, the Dragon Hunters' ship, The Reaper, became entrapped there along with the Dragon Eye.

Trader Johann used the graveyard to store all his good and wares on the derelict ships there, except The Reaper. Following his escape from Outcast Island, Dagur the Deranged, Savage, and their Berserkers took Johann's ship and sailed there to take his goods in order to rebuild Dagur's forces. Hiccup and his riders got there first, securing most Johann's goods. Hiccup and Toothless then explored The Reaper, finding the Dragon Eye. However, Hiccup was then confronted by Dagur and his men, who captured his riders. Dagur then demanded the Dragon eye from Hiccup.

Dragon Eye of the Beholder, Part 2
After Dagur was then given the eye, he left. Hiccup pursued him but then Dagur fired his catapult at The Reaper, sinking it. Luckily, Hiccup and Toothless were able to save the riders and recover the Dragon Eye.

Gone Gustav Gone
Dagur and his then returned a few days later to recover the traps and items from The Reaper. After that, Dagur and his men left The Reaper on the surface.

Night of the Hunters, Part 1
The Riders then returned to search The Reaper for clues as to where the Dragon Hunters were taking Stormfly.

A Time to Skrill
Hiccup and Toothless then returned when the Frozen Skrill was out for revenge on them.

Trivia

 * While being displayed hazardous early on in the series, the riders seemed become more familiar to the Graveyard as time goes on. Hiccup once even considered it out as a safe refuge