Gloucester pioneered the fan vault, a feature of the most elaborate English gothic buildings.

The cathedral's cloister contains the earliest fan vault.
The cathedral is full of architectural curiosities like flying ribs (also found in Warwick and Bristol), intersecting lierne vaults, and the tower buttresses encased in the walls of the south transept.
The Great East Window is a curiosity, being wider than the walls of the quire, but a beautiful one.