Query: On what continents have NBA teams played preseason games outside the US?
Context: In the early days of the NBA, league clubs sometimes challenged the legendary barnstorming Harlem Globetrotters, with mixed success. The NBA has played preseason games in Europe and Asia. In the 2006 and 2007 seasons, the NBA and the primary European club competition, the Euroleague, conducted a preseason tournament featuring two NBA teams and the finalists from that year's Euroleague.[citation needed]