We went here on a recommendation and did we regret it. Expensive, really expensive for a very disappointing meal and drinks. 6,000HUF for 2 decilitres local plonk; stop it! You don't pay that at Petrus.
The only place so far we have left feeling fleeced as foreigners. OK, ok not the only place but fully shorn.

Excellent fresh food, not that kind of upmixed things. Fish selection is very nice and prepared directly.

Very interesting place, especially in summer time, a little bit to much traffic and, therefore noise around.

Prices are in the upper category, but you get a lot of good taste. Wines are definitely overpriced. Anyhow, try the cakes - they are a dream.

Manna bills itself as an "euthentic lounge," and no, we have no idea what that means, either. But we do recall that "Manna" was the food that God dished out to the Israelites when they got stuck in the desert during the Exodus, which is a nice metaphor for this swanky little restaurant/bar perched above the "rear" entrance to the alagút (tunnel) that runs under the Buda castle. Because if you are wandering around the castle and you happen across Manna, you might be just as relieved. On the other hand, the original Manna was free, and this one is rather pricey. Still, it's very much worth stopping by - or taking its groovy online tour - if only to appreciate the audacity of the proprietors, and the fact that Budapest now has more sleek dining/drinking spots than it knows what to do with.