Sopot Makes Return To ATP Challenger Tour The ATP Challenger Tour is back in the Polish seaside city of Sopot, with former doubles star Mariusz Fyrstenberg leading the charge as tournament director. The city previously hosted a Challenger from 1998-2001, as well as in 2011, with David Ferrer among those lifting the trophy. Sopot is a major health-spa and tourist resort destination, boasting the longest wooden pier in Europe.