I love church bells and their sound.
I’m not quite sure but I would guess that there might be some 1,000 bells in Mallorcan chapels and churches, not forgetting the bells at our majestic La Seu (Cathedral) or the various town hall bells.
Palma’s Cathedral is the proud home to a dozen cast iron bells, five of which date back to 1312/15, making this the most important mediaeval bell synchrony in Europe. Sadly I could not find a photo of the bells’ arrangement of La Seu, other than a detail of n’Aloi (photo bottom). N’Aloi, the largest of the bells at Palma’s Cathedral, dates from 1592, has a diameter of 200 cm and weighs a hefty 4,632 kilogrammes.
Instead I offer you an image of the bells of the Torre Rubí in Manacor, part of the church of Els Dolors, dating from 1902. One of the bells is also called n’Aloi.
The photo (top) was taken from the Internet. My thanks go to diariodemallorca.es and the photographer, S. Sansó. The photo (bottom) was also taken from the Internet, thanks to campaners.com.
Muchas gracias.
The Mallorca Photo Blog 
I seriously doubt they were cast iron; otherwise they’d be all rusty, and (correct me if I’m wrong) cast iron didn’t really come into use in europe till the 1500s in any case. Bells are normally made of bronze even today, because bronze (80% copper, 20% tin) has just the right hardness/softness that makes it sonorous and long-lasting.