Palácio de Karnak is the seat of the Piauí state government and the most formal building in Teresina's centre. Its white neoclassical facade, gardens, and ceremonial role give the otherwise low-rise capital a clear civic focus.
You are most likely to see it from the outside while walking between Praça da Liberdade and Praça Pedro II. Even without a tour, it helps explain Teresina's origin as a planned administrative capital rather than an old colonial port.