This sumptuous Gothic mansion, built in the 1880s for the Gresham family, became home to the Catholic bishop of neighboring Sacred Heart Church in 1923. Venture past its forbidding exterior, and inside it’s quite glorious, centering on a huge rotunda, and complete with hidden back stairs, false-lit stained glass and other fun features. Self-guided tours explain its history; discount coupons are widely available.
On the 3rd Sat of each month, docent-led 'Basement to Attic' tours (per person $30) take in areas that are otherwise off-limits.