Currently, without mods or access to the admin panel, the only way to access The Tower of Bats is by climbing it. After Update 3.0 releases, you may be able to access the Tower of Bats by using the Summon Bat Demon sorcery to glide over to the tower. However, this will require a tall vantage point, and the effort spent climbing to that spot is better spent climbing The Tower of Bats in an intended way.