For tourism the seaside/ beaches is universally known to beat landlocked citys, so berbera, mogadisho and bosaso have the edge hargeisa. Safety and security is very important which rules out mogadisho. so either berbera or bosaso if structurally invested in: roads, international standards airports, hotel resorts. But as long as there is AMISOM, war, terrorism damaging the name of the Somali peninsula there will not be large scale tourism.
