Well of Transposition

You conjure two connecting 5 foot-wide wells of energy, one on the floor/ground under your feet and the other on a surface you can see up to 30 feet from you, which lasts for the duration of the spell or until you lose concentration. When you cast this spell you can instantaneously appear at the other well. Any medium or smaller creature can use a bonus action on it's turn to instantaneously travel from one well to the other as long as the destination is unobstructed.

When a creature tries to travel through the wells, you can use your reaction to stop concentrating on the spell, dealing 4d10 force damage to the creature, as the well disappears.