Maintained by the College of Physicians, this unique, only-in-Philadelphia attraction is a museum dedicated to rare, odd or disturbing medical conditions. Not for the squeamish, its nonetheless fascinating exhibits include a saponified body, a conjoined female fetus, incredibly realistic wax models of medical conditions and skulls by the dozen.
The College of Physicians also hosts many events in the building, including classical music concerts and lectures – check the website for details. Note there's $2 off admission on Monday and Tuesday.