This is a so called Elf-Tower from our Leniland Story Server. (Minecraft Java 1.18)
In this tower the Elf Magicians of Leniland reside and guard their lands.
The Tower has a basement, so when you paste, it goes 4 Blocks into the ground below your feed where you are standing.
It is one of many pieces of the Leniland Story Server, making it possible to create your own adventure map.