The Charola of the Convent of Christ at Tomar
The Charola, the round Templar oratory inside the castle at Tomar, built in the late twelfth century on the plan of the Holy Sepulchre. The order's Portuguese headquarters was a working fortress with a church in the middle of it.
Templar building was engineering before it was architecture. Their castles had to hold a small permanent garrison against a much larger field army, which meant concentric walls, water stored inside, fields of fire that crossed, and towers that could be defended after the curtain fell. The round church at the centre of Tomar was liturgical and also practical: a keep with an altar in it. See the Knights Templar and technological innovation in banking, codes and castles.
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