Ever wondered how time travelling with artefacts work? It is a lengthy complicated procedure.
First the artefact must be built with lightweight but sturdy metal. It must be able to withstand time and age. It must always have a fair amount of time and space particles inside in order to time travel.
But with great power comes great responsibility. Many try to use those artefacts for selfish intentions, like cheating death or to simply tamper with history. The main rule of time travelling is not to touch anything, for even the smallest accident has the biggest impact on the future.
Most of these artefacts were eventually destroyed. By either the anxious makers or by the threatened houses of politics. Nothing survived the destruction of time-travelling machines, watches, phones, nothing.
All but a single, beautiful hourglass necklace. It was the ultimate time travel device. It's maker, a Swedish Professor named Alexandre Elkstein found that his creation had perfected the use of time travel. So far there were no complications.
To protect the perfect time travel device, Alexandre opened a time and space portal and hurled the necklace inside. The portal closed long before authorities could arrest the professor for his creation.
The necklace continues to float, lost in space and time until The Chosen One is found. Only he or she could possess such an artefact and use it with great caution.