Let the Spree River murmur you to sleep while you're snugly ensconced in this two-boat, floating hostel with a rocking bar right by the East Side Gallery. Cabins are trimmed in wood and sweetly snug (except for ‘1st class’); most have their own shower and toilet. In summer, you can also rent a tent on the rooftop of one of the boats.
Optional breakfast is €8. There's a two-night minimum stay on weekends and a one-time fee of €5 for linen and towel in the dorms (or bring your own). The party zones of Kreuzberg and Friedrichshain are handily within staggering distance.