A biosphere.
The Safety features were the iron in the dome, creating a sturdy dome.
Dome arch
"A biosphere is a sealed glass dome that has all the features of Earth"- Science textbook
A Sealed glass dome that replicates all the features of Earth is commonly referred to as a "terraformed biosphere." It is a controlled environment designed to simulate Earth's conditions to support life.
The Whispering Gallery in the dome and the Crypt.
Dome
Devil on My Back by Monica Hughes. This book was written in the 80s and features characters who live in a dome /arcology which I believe is called ArcOne. From Amazon (user review):
A batholith, a volcanic neck, and a dome mountain.
they were called teppes
A round dome-shaped building is typically called a "dome" or a "cupola." These structures often serve as architectural features in various types of buildings, including churches, government buildings, and museums. Notable examples include the Pantheon in Rome and St. Peter's Basilica in Vatican City. Domes are celebrated for their aesthetic beauty and their ability to span large spaces without internal supports.
A domed shrine is called a Stupa.
An igloo