The Boulders Gym

V10

{0}: You may have an equipped creature you control climb The Boulders Gym, then put a climb counter on The Boulders Gym for each equipment attached to that creature.

When The Boulders Gym is topped, tap it, and it doesn't untap during your untap step. Then you get an emblem with "Whenever an equipment you control enters, you
may pay {1} to attach it to target creature you control."