Carambar

Address: Rathausstraße, 1, Berlin. A quick check on the map can help confirm the entrance and the easiest approach.

Looks like they're open every day, so you don't need to worry about timing your visit around a closed day.

According to available data, this is a restaurant. Better suited to a more relaxed visit, a full meal, and a sit-down experience.

Internet access is available. If you're planning to work or stay for a while, it's still smart to check how reliable the connection actually is.

Smoking and non-smoking seating are separated. That can work well, though the comfort level still depends on the layout and ventilation.