Neuschwanstein Castle

Fortress (Any Planeswalker or creature you control
can enter this building, making it a defender with a
0/10.)
•Add {c} and {s} to your mana pool.
Construct 5 (This enters with 5 structure counters on
it. If it ever has none, it's destroyed. Structures can be
attacked as if they were planeswalkers and targeted by
"any target" effects. Damage dealt to structures
removes that many structure counters.)