. >>> blast in beirut, mohamed chatta, an outspoken are speaker,. >>> south sudan, said they would step in if the two sides failed to end the fighting in four days. another 72 u.n. peace keepers arrived in south sudan's capitol on friday, joining thousands who are already there. those are the headlines, america tonight is next. >> on "america tonight", bis buzz, behind a legalized cash crop now hit a new high. >> at the end of the day, it makes me a little bit giddy. >>> also tonight the arc of greatness in our everyday lives. how we take for granted these extraordinary views. and the artists behind them. >> it's almost as if they were dropped here from the 14th century building some of the greatest buildings our country has ever known. >> and footsteps. >> tracing the past, an ancient art and the experienced spirits aging to lead its rebirth. good evening, thanks for being with us, i'm joie chen. in the state of colorado, recreational pot smokers, beginning on wednesday marijuana users will be able to buy the drug legally without having to show any medical need. about 20 pot shops half