Simplify the following text for a Grade 9 native English-speaking person.
Original: Sanga Monastery was built amid the ruins of the castle ( or fort ) Taktse ( also Dagtse ) Dzong ( formerly Dechen Dzong ) on the hill top .
Simplified: Sanga Monastery was built in the ruins of the castle ( or fort ) Taktse ( also Dagtse ) Dzong ( formerly Dechen Dzong ) on the top of a hill .