Concierge.com's insider take:

This is the best place in Prague to indulge czarist fantasies and play at 17th-century aristocratic life—or to stage a marriage proposal. The building, which dates from the 1600s, went through various incarnations before settling into its current role as the Prague Conservatory. Enter the gorgeously faded candlelit grandeur of the second-floor restaurant (the former student dining halls) via a spectacular sweeping staircase, and take your place for the nightly theater of formal service. Or, if it's summer, go for the terrace overlooking the Prague Castle gardens. The novo-Euro dishes are mostly very good and not priced to rip off tourists (this is just as much a locals' place). A head of roasted garlic arrives with the bread, then it's on to dishes such as mushroom- and truffle-stuffed quail with kumquat sauce, minted lamb seasoned with smoked salt, or seared tuna with tomato-olive compote (the menu changes three times per year). It's a dress-up evening, but not in the manner of grand-hotel dining rooms—this is decadent chic in a palace that has seen better days.