Wall

Protects your base from zombies by blocking their movement.

Tips

 * These are important late game, but you may not need to build them until waves 35-40.
 * When building your outer walls, don't put then directly next to each other. Leave a space between each row to mitigate the damage of Screamers.
 * Walls get expensive fast. Keep only one row untill you really need more.
 * Use your boss money to help keep walls up. You don't need to max out every building.
 * If you build your base on a wall or in a corner, Try to triple layer your walls where the attacks are largest.
 * If a singular wall keeps dying, level it up. it's increased health will stop it from being destroyed and save you a lot of gems.
 * You may need to double or triple layer your walls when going late game.

Characteristics at different levels (Easy)
a

Trivia
 original reference
 * Walls have the second most health out of any building in the game, behind the base.