The Streletzki Group is the builder, owner and operator of the Estrel Convention Hotel Berlin and the Ellington Hotel Berlin. The Estrel, with 1,125 rooms and approximately 20,000 sq. m. of convention space, is Europe's largest convention, entertainment and hotel complex. UPPER SPREEGOLD combines the advantages and service ethic of the classic apartment or hotel concept with the ease and comfort of your own four walls – so that you can feel totally relaxed.