Watched this documentary on Gothic cathedrals in France on SCV. Buildings made of stones in the past had tiny doorways, so as to support the weight of the entire building. Gothic architecture, however, revolutionized that.
Gothic architecture has three distinct characteristics which set it apart from Romanesque:
1. pointed arches
2. flying buttresses
3. ribbed vault
These developments allowed the architects to make the church much larger, higher and brighter. By transferring the weight of the ceilings outward thrust to the flying buttresses, they were now able to place huge stain glass windows in the walls which allowed the once dim Romanesque Cathedral to be transformed into a a bright Gothic Cathedral.
Sorry for the extra information... but i am really awestruck by how comprehensive the documentary was... so much so that even someone who has zilch knowledege about architecture could be so fascinated...

Our ancestors are amazing.. they have no sophisticated tools, but are able to construct such grand and beautiful buildings.
Our counterparts are equally amazing... inventing high-tech systems to deduce what our ancestors did and solve mysteries of the past...
Guess, the bottomline is, there are so so SO many things to learn about in this world... and that i'll never look at the cathedrals the same way again.
If only I can get to see them with my own eyes. Soon, I hope.