To walk its streets is to burn in its beauty.

City of Brass

Whenever this land becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Mystery Booster 2

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

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"There is much to learn here, but few can endure the ringing of the spires."
—Nulakam the Archivist

Double Masters 2022

If you tap City of Brass while you are casting a spell or activating an ability, its ability will trigger and wait. When you finish casting that spell or activating that ability, City of Brass's triggered ability is put on the stack on top of it. City of Brass's ability will resolve first.

On the other hand, you can tap City of Brass, put its triggered ability on the stack, and then respond to that ability by casting an instant or activating an ability using that mana. In that case, the instant spell or activated ability will resolve first.

The first ability triggers no matter how the land becomes tapped.