Handle HUGE Worlds

I have created a HUGE scene(a Town) and its laggy(low FPS).
How I can Handle Huge Scenes?
It is possible to create a Chunk System,wich is loading only the important part of the map ?
And How I can do this  
(Sorry for my bad English)

LOD is what you are thinking about. You can also go about Occlusion Culling.

But you can only use it in Unity-Pro ! Is there a free way to use LOD/Occlusion Culling ?

Load the level asynchronously

putzi wrote:

But you can only use it in Unity-Pro ! Is there a free way to use LOD/Occlusion Culling ?

You should check out this asset you can get which is $10, which is a LOD system for unity Free.
http://u3d.as/content/brilliant-game-studios/smart-lod/3gZ

Also here is a free asset from M2H which provides a culling system for unity free. Project files should be on this page: http://forum.unity3d.com/threads/m2hculling-optimize-your-game-culling-system-for-unity.52130/

Hope I helped.

MisterNinjaBoy wrote:

LOD is what you are thinking about. You can also go about Occlusion Culling.

You could also pre-load the level? I have heard of people doing this to mimimalize the lag.