The universe of Celtic Heroes is currently divided into 3 main areas and 3 secondary areas,* which are included in the main areas. Within the areas are Leystones that allow players to quick-travel if they are not overburdened (10 items max can be carried in the inventory, but that limit can be increased upon purchasing Backpack extension in the Platinum shop.)
Lir's Reach was the first main area implemented in Celtic Heroes, and it was the only one accessible back then. This area is destined to beginner players, from level 1 to 20 approximately, since its monsters have a level ranging from 1 to 22 except for the boss found just west of the skullcrusher camp. The rockbelly is the boss there surrounded by jotun frost splitters. Which are lvl 80s.
There are also 3 Red bosses , those who drops remnants needed for the warden upgreaden quest. Those bosses are : Stonefang , Redbane and rockbelly
Lir's Reach is also the only main area that currently includes secondary areas, even though more secondary areas are going to be added in the upcoming version the game.
Farcrag Castle is the first secondary area that a new player would most-likely visit. It is the smallest area in the game and only includes one Leystone, Farcrag Castle Courtyard.
But in the new update, Farcrag castle has had more npcs, an arena to fight in, dunkseig sewers entrance, and much more. It is probably the place where most high levels stay to duel and buy items.
Crookback Hollow is the second secondary area of Lir's Reach. It features an underground maze filled with attackable NPCs with levels ranging from 6 to 24 except for the boss found in crookback hollow called bonehead.
Dustwither Catacombs can be considered as an extent to Lir's Reach because it includes monsters from level 21 to 50. Therefore it is a good place for players who are level 20 or above.
The Catacombs have three bosses who sometimes drop an upgraded version of Redclaw, Silverleaf, Sorcerous, Darkrun and Highroad armour, which are very popular among low and medium-level players; they might also drop valuable gems, used in the Meteoric weapon quest.
Dustwither has bosses such as Avatar Of Donn, Disciple Kiara, Disciple Ducarius
Shalemont Ravine is destined to medium-level players as the levels of the monsters who spawn there are included between 28 and 60. There are 3 Leystones in this area, MacCroin Encampment, Greygorge and Shalemont River.
This area features a medium-hard boss, Atrisal the Invincible, who gives 3 drops to the group that kills it; The drop may be either an Ancient item (some are not sold by merchants) or a Golden Ingot also red book bindings or red book cover used in the assassinate quest for rogues, which can be used in the Meteoric weapon quest, along with a significant amount of gold.
Also, Shalemont includes the popular quest, "The Defector"; 13 mini-bosses (referred to as "defectors" by many players, though in the story, the Defector is actually the one who gives you the quest) spawn in the area and may drop rare items (such as the Wall of Eternity that can be obtained from Laird the Guardian)
Two extra secondary zones are going to be added in this area, it was confirmed by the Admin on the CH Forums, and will be located at the castle at Shalemont River, behind Atrisal, and in the cave near Greygorge.
Stonevale is the hardest area currently implemented and is destined for players over level 50. The levels of its monsters range from 53 to 105.
There are also 5 hard bosses that drop 3 items, sometimes known as 'tomato bosses' in game terminology; either Disc Fragments or Croms; Fellfire, Chillmist, Starspell, Spirehoof the Corrupted and Falgren Bloodbinder. These 5 bosses have mini-bosses that only drop 1 Disc Fragment Charfire, Crystalmist, Shimmerspell, Crumblehorn , and Brutus Bloodbinder. The Otherworld In the new update of Celtic Heroes there are plans for a new area called the Otherworld - if you play the game you may have heard it mentioned during the Christmas patch by some of the faeries, or elsewhere. If you havent then you will soon find out - it is meant to be an area full of high level mobs (creatures, things you attack), destined for players at least level 80, if not higher, with big, difficult bosses of levels up to 130-140. As it is not yet released the rest of the information is secret, like the amount and the names of leystones, the names of mobs and bosses, etc.