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... Station Zoologischer Garten (travel time is 12 minutes)
Recomended hotels:
Park Inn Hotel in Berlin
https://www.parkinn.com/hotel-berlin
This is the hotel right next to the DFN offices.
Alternatively have a look at the following list of hotels, which are all in walking distance to the DFN Offices and Alexanderplatz:
Hotel Motel One - Alexanderplatz
https://www.motel-one.com/en/hotels/berlin/hotel-berlin-alexanderplatz/
Hotel Motel One – Hackescher Markt
https://www.motel-one.com/en/hotels/berlin/hotel-berlin-hackescher-markt/
Hotel Indigo
https://hotelindigoberlin.com/
B&B Hotels Berlin Alexanderplatz
https://www.hotelbb.de/de/berlin-alexanderplatz
Hotel Hackescher Markt
https://www.hotel-hackescher-markt.com/en
No-chain hotel. Just one stop (2min) away from Alexanderplatz by S-Bahn.