Darillium Darillium was a planet known for its Singing Towers , a pair of monoliths . The Twelfth Doctor took River Song to see these towers the last time she saw him before she went to the Library and met the Tenth Doctor . Astronomical data . Darillium was located in a galaxy near the Andromeda Galaxy . The planet had several rings around it and a large number of non - spherical moon s . Seen from afar , Darillium had a reddish - brown colouration , likely due to having a largely rocky surface . The atmosphere was breathable as well . It rotated very slowly ; in human terms , a night lasted 24 years . Darillium also contained a cave system with a crystal layer . When the wind blew though the caves by the Singing Towers , it would harmonise with the layer and cause a song to be produced , the reason why the monoliths had been named as they were . At least one species of bird was native to Darillium , during the Twelfth Doctor and River ' s visit , as a flock was seen gathering near the Singing Towers . ( TV : " The Husbands of River Song " ) History . In the TARDIS , an older Eleventh Doctor and River Song stumbled upon his younger eleventh self before visiting Darillium , and the two Doctors briefly discussed that it was her last meeting with them . ( HOMEVID : " Last Night " ) This conversation made him unwilling to go to Darillium yet and the Doctor cancelled his plans at the last minute . He continued to back out of this date several times . After the " Harmony and Redemption " was struck by a meteor storm , it went on a crash - course for Darillium . The Twelfth Doctor and River attempted to stop the crash , but ultimately were forced to flee into the TARDIS . The ship crashed on Darillium , leaving no survivors , save the Doctor and River , who were in the TARDIS during the crash , and Nardole and Ramone , whose heads were later able to take control of Hydroflax ' s body , which was recovered from the wreckage . After the crash , the Doctor decided to stop fighting the inevitable and take River on their last date together . The Doctor met a man named Alphonse who had come to the wreckage of the " Harmony and Redemption " in search of survivors . The Doctor recognised that he was benevolent and , in preparation for his date , gave Alphonse the Halassi Androvar diamond , telling him to redeem the reward and use the money to build a restaurant in front of the Singing Towers . The Doctor then travelled forward in time to after the restaurant was built to make a reservation . Although the restaurant was fully booked up to Christmas Day in four years time , he made a reservation for " table on the balcony with a view of the towers " and travelled to the day of his reservation with River . Having been knocked out by the force of the crash landing , River eventually awoke and left the TARDIS , entering the restaurant and using a special perfume spray to change clothes . There , she found Nardole and Ramone working at the restaurant and was greeted by the Doctor , who gave her her first present from him : a sonic screwdriver . The Doctor took her to the balcony to see the Singing Towers . River revealed knowledge that this was the last night they spent together though the Doctor refused to confirm it . He eventually told her that night on Darillium was twenty - four years long , giving them plenty of time on their last date . ( TV : " The Husbands of River Song " ) River told the Doctor in the Library that " the last time I saw you — the real you , the future you , I mean — you turned up on my doorstep with a new haircut and a suit . You took me to Darillium to see the Singing Towers . What a night that was . The towers sang and you cried . You wouldn ' t tell me why , but I suppose you knew it was time . My time . Time to come to the Library . You even gave me your screwdriver . That should have been a clue . " ( TV : " Forest of the Dead " )