The New Media Consortium
On my travels I went to see The New Media Consortium Campus in Second Life. The NMC represents the largest educational project in any virtual world, comprising the efforts of over 120 institutions.
The NMC has been around since 2005 and they are an educational community by sharing open source content. They have created many projects including amphitheaters, module building units, avatars, furnishings, and science equipment... They are available on their learning sim.
One of the famous builds I have seen on this sim is called Primolution, this is an amazing build it shows how Second Life is evolving and now to Mesh.
This sim has many other famous builds it is a must see place I definately recommend it as one of the places to visit within Second Life.