We visited an East End basement bar years ago in the style of the owner’s East European babushka’s home and some pretty weird cocktails - eg a glass pipe with a liquid, you pour another liquid and it “smoked”.
Went to the Aqua rooftop bar the other day - it was ok.
Can anyone recommend good options that are unique?
I don’t know about their cocktails, but Bar Elba in Waterloo is a nice rooftop bar – good vibes for a medium-to-large social event. The Alchemist (like Scott suggested in another comment) has very interesting weird cocktails, but personally, the novelty wore off after a couple of visits as the cocktails themselves are… OK.
Other nice cocktails bars that I can recommend are Callooh Callay and Cahoots.