The keys were supposed to be left in a restaurant opposite the flat but they didn’t have them. Emilio did respond to my worried message that the keys were under the mat - which they were but we were lucky that a neighbour came out or we couldn’t have got through the door of the block. On our last night Xmas day we arrived back to the flat to find a Brazilian family outside. They had flown from Brazil overnight only to find the flat was double booked. We ensured they had found other accommodation but were prepared to squeeze them in if they were left homeless as they had young children. Disastrously poor administration. The flat itself was clean, dry and perfectly adequate. As perhaps expected from the low price it was more like student accommodation than a holiday let but perfectly adequate and a very good, central location. Just a bit tired - shower didn’t work very well, mismatched and old towels etc.. Fine for a central Berlin stay if you are not too fussy but disastrous admin.