This is a classic French structure, a Chateau. If you do not spawn right near it, use this command:

/tp @a 0 6 20

this will tp, or teleport, you to the front of the structure. Be sure to look for the hidden button with the escape route! Do not cheat and use gamemode 3 though, which is spectator. I helped create this, but PotatoOlive, who I do a bunch of maps with, created most of this. PotatoOlive told me to post this. Thank you PotatoOlive! So yeah......... this is a structure, it is 1.12.2 or later, and other than that, the only thing I have to say is have fun!

Commands to use:

/weather clear Sets weather to clear
/time set day time to day
/tp @a 0 6 20 teleports you to the front of Chateau