Some commentators refer to it as the rise of Dark Tourism: the desire to visit places that played significant roles in disasters or evil acts. The history of slavery fits uneasily into that category. Uneasily, not because human ownership and forced labor aren't evil, but because visits to slavery sites are usually an attempt to educate, or grapple with a dark past. This week, Associated Press correspondent Russell Contreras takes us to slavery museums in Liverpool, England and Lagos, Portugal. And on My Favorite Trip: former AP travel editor Beth Harpaz recounts some of the singular joys of New Mexico.