The Glass Temple, a few kilometers from the shore of the Horn of Africa, the magical, technological, and economical hub of Africa, has gained recognition from all around East Africa and Arabia.
Like the name implies, it is a giant temple made entirely out of glass. Inside the temple, there are libraries, mysterious rooms where mysterious people do mysterious things, a small university, and prayer rooms. Considering the fact that magic exists, what would be a reason for this glass temple to exist?
Magic System:
Magic is transformation/conversion of energy from one's own soul
"Programming" magic is possible through complex seals and storing bits of soul within the seals
Physics mostly apply
Sunlight does not fuel magic
Setting:
Pre-medieval mundane technology, but magical advances allow for use of things like electricity in a magical context
Edits:
1) The answer doesn't necessarily have to relate to magic, but magic can be used to give the glass properties that it might not normally have
2) I edited the rules of the magic system to exclude fueling magic from sunlight