Rope Trick
No spells or attacks can cross into or out of the extradimensional space. Creatures inside the extradimensional space can see out of a 3-foot-by- 5-foot window centered on its entrance. Creatures outside the space can spot the entrance with a Perception check against your spell save DC. If they can reach it, creatures can pass in and out of the space.
When the spell ends, anything inside the extradimensional space falls to the ground.