The largest geode ever found is the Pulpi geode, located in Pulpi, Spain. It was discovered in 1999 in a abandoned mine and is estimated to be around 11 meters (36 feet) tall and 8 meters (26 feet) wide.

It's filled with transparent gypsum crystals that can reach up to 2 meters (6.5 feet) in length. The geode is so large that it's impossible to see the whole thing from any one spot.

While other geodes have been found that are bigger in terms of volume, the Pulpi geode is the largest in terms of the size of its interior cavity and the sheer size of the crystals it contains.