Dragon's Dogma Side Notes

Grand Cathedral http://dragonsdogma.wikia.com/wiki/Grand_Cathedral
During the game's timeline,Pablos, the innkeeper of Cassardis, he tells that the Faith is sending believers to the Grand Cathedral on the mainland to get first hand accounts of the dragon -- apparently to study it.

Great Library http://dragonsdogma.wikia.com/wiki/Great_Library
When speaking with Merrick, an inhabitant of Gran Soren, he tells of this place being situated on the mainland that holds many books. He states "It's the finest collection of letters in all the lands".During conversation he tells of his journey towards the mainland and of his arrival back in Gransys where he mentions that "the people are cowering in the shadow of the wyrm". This means that he must have undertaken his journey afore the player encounters Grigori in Cassardis and become the Arisen.

Hearthstone http://dragonsdogma.wikia.com/wiki/Hearthstone
Hearthstone is one of the countries neighboring Gransys. It is ruled by a duchy much the same Gransys is. Mercedes is an agent sent from Hearthstone to Gransys to provide help from the dragon attack. It is believed to be bigger than Gransys. The Country is part of an allied pact made from an undiclosed amount of countries to provide help from the dragon.

Mainland http://dragonsdogma.wikia.com/wiki/Mainland
The mainland is a place which is not visitable by the Arisen. Some inhabitants of Gransys speak of it, either out of own experiences or tales heard from others.
The geographical location of this mainland is unknown, though it can be assumed that it is attached to the Liogran Peninsula upon which Gransys is situated. The only thing known about the mainland is that is has at least one city, a structure known as the Great Library, and a structure known as the Grand Cathedral.
Although being a deity with godly powers, the Seneschal only seems to watch over Gransys only and does not mention anything about the mainland.
Most conversations people have about the mainland have taken place in the past compared to the time in which the game is set. Merrick, for example, says he went to see the Great Library and upon return saw people frightened due to the wyrm's presence, while Brice states that he ran from the wyrm before, back when he worked in a city on the mainland seeing many people got trampled by others during their flee from that city.
During the game's timeline Julien speaks of the mainland, saying he was sent from the kingdom over there to aid duke Edmun Dragonsbane against the wyrm.
Also during the game's timline, Pablos mentions the Faith is sending believers to the Grand Cathedral on the mainland to gather accounts from those who saw the dragon -- apparently to study it.
Although the country of Hearthstone is a neighbor of Gransys it is unknown whether the border dividing these two countries is either natural or artificial. It thus remains uncertain if Hearthstone is to be found on the same island/continent as Gransys or not. This same speculation can be made about the country of Baldoa as well.
Perhaps the mainland will be of significance in the announced sequel of Dragon's Dogma and may become a playable location.