The inside of the keep is the largest safe zone.

Safe zones are places where a player can not be damaged by a monster and/or another player. Surrounding any non-aggressive NPC is an area where monsters and other players can not attack. The largest one of this type is the keep of Sherwood Castle. Technically, while other players can still hit you, places such as the inside of Sherwood Castle and huts, are safe zones because monsters either do not or can not get to you. After July 2010 safe zones became very scarce because monsters had the ability to use long ranged attacks. Also monsters used to not be able to climb rocks, but the recent updates have changed this.

If the player fires an Arrow to a monster and then runs to the safe zone, the monster will enter the safe zone and attack there. This is the only known way to attract monsters to safe zones.