Great fuss free stay at Mitte area. Walkable to Berlin's museum island and there are lots of restaurants nearby. Area was very safe and clean too. We were given a free upgrade from a S sized room to M sized when we check in. Room was clean and tidy. There isn't an electric kettle in the room so if you need hot water, you'll need to go down to the lobby area to get some (it closes at 10pm). WiFi was weak and not sufficient if you're working remotely. Overall, great stay at Calma and would recommend it to all.