Down in Spain at the moment and it seems to just be the small bottles of gas that are available, do you know if this is the same around the Med? I'm missing having 2 large bottles that fill the whole locker like I used to in Scotland.
I assume, when you speak of the small bottles you are referring to the camping gas 907 2.7 kg containers.
I believe this is butane. Many of the Spanish petrol stations sell or exchange the larger 4.5 kg Calor Gas butane containers, having not personally experienced these before I do not know wether any type of adapter would be necessary