Teatro Nacional de São Carlos
Inaugurated in 1793, this grand neoclassical theater was inspired by Venice's opera house. You have to see the main hall to appreciate the building's splendor. The stage itself is rather plain, but the five tiers of private boxes on either side draw the eye to the domed royal box, awash with gold leaf and held aloft by soaring columns. Two cherubs hold aloft the royal coat of arms. The theater has its own choir, is home to the Portuguese Symphonic Orchestra, and hosts music and dance performances, as well as opera. Book guided tours in advance by email.