What are pigeon houses?

Search: pigeon houses

Why: In this collection of aerial photography by Yann Arthus-Bertrand:

Pigeon Houses Mit Gahmr Delta, Egypt

Answer: Well, they are houses for pigeons! But why? Because:

Pigeon is a part of the daily diet in many parts of Egypt

Horf! Also, they use the droppings as fertilizer. The houses, called dovecotes, are made of natural mud brick.

Source: EarthArchitecture.org

The More You Know: Other interesting images from that collection:

Sha Kibbutz, Israel

Copenhagen, Denmark

Denver, Colorado