Strange thing?

I started a new Minecraft world and am spawning in the forest, but I found this structure, what is it?

PS is Minecraft XBOX

These are stones that simply spawn everywhere as decoration in the biome. Simply dismantle and take with you. There's no easier way to get to the Moss-Cobbel.

Quite normal Steinhagen that can be found in this biome.

How long have they been there?

These can be found in the Giants Spruce taiga

Ever since the biome has existed. 2013.