Arches inside a stone building

Hagia Irene in Istanbul (ancient Constantinople)

What is an apse?

An apse is a rounded end of a building. You most often find an apse in a basilica or a church. But sometimes a private house or a Roman bath building has an apse too.

What’s a basilica?
Roman baths
Parts of a church

Chartres nave

Chartres nave

An apse is like half a dome

It just means that the end of the building is curved in a semi-circle (half a circle) instead of being flat, like the wall of your house or school probably is. The roof of an apse is like half a dome.

More about domes
And about arches

Why did people build apses?

Floor plan of Chartres Cathedral

Floor plan of Chartres Cathedral

Apses make a building look fancier, or more complicated. If you’re going to be doing something important at one end of your building – like saying Mass at one end of a church, or judging court cases at one end of a basilica – then an apse makes that end of the building seem more important than the other end. That way, the people who are watching will know which way to look.

Learn by doing: visit a church and check out the apse

Apses in Roman Basilicas
Apses in Medieval Cathedrals

Bibliography and further reading about apses and architecture:

Arches to Zigzags: An Architecture ABC, by Michael J. Crosbie (2000). Shows what an arch is, or a gable, or an eave. For younger kids.

Eyewitness: Building, by Philip Wilkinson, Dave King, and Geoff Dann (2000). Lavishly illustrated, like other Eyewitness books for kids, and with good explanations of most architectural terms.

City: A Story of Roman Planning and Construction, by David Macaulay (1983).

What’s a nave?
And what’s an aisle?
What’s a basilica?
What’s a cathedral?
Romanesque architecture
Gothic architecture
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