Maybe, but I doubted that the UK had any point below sea level, but it seems that I was wrong:
https://en.wikipedia.org/wiki/Holme_Fen#Holme_Fen
2.74 meters below sea level.
I've had a drink at probably the second lowest restaurant/bar in the US which is part of the Furnace Creek Inn, in Death Valley. Probably the lowest restaurant/pub in the US is the one that is part of Furnace Creek Ranch which is about 190 feet below sea level. At the time I had the drink at the Furnace Creek Inn I wasn't aware of the importance of having a drink at the lowest point in the US or of course I would have had a drink at the Furnace Creek Ranch as well.
I've also had a glass of wine with a very nice dinner at the top of the Palm Springs Tramway, which might be the highest restaurant in California. It's probably around 8,200 feet. But you can probably get a drink at the little restaurant at the top of Whitney Portal which is at about 9,000 feet and maybe that's the highest restaurant in California.